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PHYSIOLOGY: 



GENERAL and OSTEOPATHIC 



A REFERENCE AND TEXT BOOK 

For Osteopathic Students and Physicians 



BY 



J. DEASON, Sc. B., M. S., Ph. G., D. O. 

\\ 
DIRECTOR OF THE A. T. STILL RESEARCH INSTITUTE 

AND FORMERL Y PROFESSOR OF PHYSIOLOG Y IN 

THE AMERICAN SCHOOL OF OSTEOPATHY 

Member of the American Osteopathic Association 
Member of the Missouri Osteopathic Association 



PRESS OF 

THE JOURNAL, PRINTING COMPANY 

KIRKSVILLE, MO. 



-» «3n 









COPYRIGHT, 1913 

BY 

J. DEASON 






INTRODUCTION. 

The study of physiology is far from being a complete science. 
Since this subject deals with the structure and functions of living 
organisms it becomes much more difficult to measure and express 
our results in numbers than in such sciences as physics and chem- 
istry, and until we are able to do this physiology will continue to 
be the results of theoretical speculation rather than a definite 
science. This, however, is wholly different from saying that 
there is nothing definitely known relative to the functions of 
living structures, for on the other hand we are greatly indebted 
to the many research workers and clinical investigators who have 
so earnestly and conscientiously solved many problems along 
these lines. The ultimate purpose of the development of physi- 
ology into a definite science should be that of gaining such informa- 
tion of living organisms that physicians may be able to treat 
human ailments intelligently. Other purposes, such as the addi- 
tion of general scientific information to other sciences, is of course 
a justifiable one, but it seems that this should be a secondary 
consideration. Research workers in physiology must, however, 
proceed along strictly scientific lines and not allow themselves 
to be biased, but must follow the results of their findings regard- 
less as to where they may lead. 

Work in physiological research has for the most part been 
done by instructors and assistants in medical colleges, and they 
have devoted much of their time to research work pertaining 
especially to drug therapy. During more recent years, since 
the endowed universities have taken up original scientific research 
in physiology, the work on this subject as well as in other branches 
has been more general. 

In medical as well as other sciences it is generally true that 
the science follows the art of practice. In medical practice this 

7 



8 PHYSIOLOGY : 

is especially true except that the results of scientific research — the 
science — has failed to confirm the methods of practice. 

Osteopathy is a comparatively new system of practice, hav- 
ing existed for only about twenty years, and yet much valuable 
research work has already been done along new and wholly differ- 
ent lines. We believe that no other school of practice has done 
as much original scientific investigation pertaining to the theories 
of its methods of treatment according to the length of time it has 
existed, and I am sure that no other school has been more success- 
ful in confirming its theories by the results of its research. That 
the osteopathic theory is fundamentally scientific no one who has 
kept up with the results of its growth, research, and practice can 
doubt. The original" plan and the fundamental principles of 
osteopathy were given by Dr. Andrew Taylor Still, a man particu- 
larly adapted to research and original investigation and who now, 
in his eighty-fifth year, is still an active student. Dr. Still has 
been a frequent and most welcome visitor in my classes at the 
American School of Osteopathy, and I am very greatly indebted 
to him for much valuable information received along osteopathic 
lines. 

Because the science of physiology is so broad, and because 
it involves so many different phases of the organic and inorganic 
sciences, no one individual can ever hope to obtain a thorough 
knowledge of the entire subject. I, therefore, frankly admit 
my inability to write a book on the subject without the aid of 
those whose original investigation and experience have been much 
more far reaching than my own. In the preparation of this book 
I admit frequent reference to the best modern authorities in 
general physiology, such as Starling, Howell, Stewart, Sherring- 
ton, Luciani, Landois, Schafer, and many others. For principles 
of physiology pertaining especially to osteopathy I have con- 
sulted the writings of Burns, McConnell, Whiting, R. K. Smith, 
Hulett, Hazard, Farmer, Tasker, and others. That these authori- 
ties might receive due credit I have frequently quoted from their 
most recent publications. 

In order that this book might be thoroughly reliable, so far 
as the part on general physiology is concerned, I have referred to 



GENERAL AND OSTEOPATHIC. 9 

and quoted from only the best authorities on this subject, using 
only most recent editions of their books. In order that the 
part pertaining to the osteopathic principles of physiology might 
be reliable I have asked assistance from our foremost research 
workers along these lines. 

Osteopathy is a system of healing which considers the funda- 
mental relations of structure to function and the co-ordinative 
functions of all body structures acting together as a unit. The 
workers in general physiology, it seems to me, do not give these 
problems due consideration and the osteopathic student cannot, 
therefore, get sufficient understanding of the subject from a study 
of the general text-books. This book has been prepared for the 
purpose of meeting this demand. It is offered only as a contri- 
bution to the general subject of physiology, as a special contri- 
bution to osteopathic literature, and is not intended to revise the 
whole trend of physiological or osteopathic thought. No attempt 
has been made to conform to the theoretical conventionalities 
so common to the general texts on physiology, but on the other 
hand the authors have endeavored to make the book thoroughly 
osteopathic because it is written for the use of osteopathic stu- 
dents and physicians. The book has been arranged in two parts, 
the first giving the principles of general physiology, omitting as 
much as possible of the seemingly unnecessary theory, the second 
giving s the results of original osteopathic research. I am very 
deeply indebted to Drs. McConnell, Burns, and Whiting for the 
excellent summaries of their research work, and to Dr. Millard 
for the drawings which he has prepared and from which all the 
colored plates have been made. I feel highly sensible of my deep 
obligation to these doctors, because without their assistance the 
book could not have been prepared, and I trust that the plan 
of co-operation will be continued and that it may result in the 
development of much valuable osteopathic literature in the future. 
I am also indebted to the editors of the Journal of the American 
Osteopathic Association, the Herald of Osteopathy, and the 
Journal of Osteopathy for allowing me the use of some of their 
colored plates, and to the C. H. Stoelting Company for the use 
of a few of their cuts. 



STRUCTURE AND FUNCTION. 

The existence of all living organisms is dependent upon the 
intimate relations which exist between the various component 
parts or structures of the organism and the work or functions which 
these structures have to perform. 

In primary physiology we are taught that "man is a ma- 
chine" and that his various working parts have their specific 
kind of work or functions to perform and that, failing in this, a 
perversion of function results and this failure of the normal func- 
tion means disease. The study of the fundamental relations of 
structure to function should then be the aim of every student of 
physiology. 

By the term structure is meant the body framework, its 
organs and other constituent parts. The term body tissue is 
applied to a structural part of the body consisting of an aggre- 
gation of similar cells having a similar function or similar functions, 
e. g., bone, which forms the frame work; cartilage, which pads 
the joints and allows movement without wear; muscle, the contrac- 
tion of which causes movement of the body levers, the bones; 
and nerve tissue, which is the body messenger and serves to con- 
nect the various structures in their functional relations and to 
regulate these functions. It will, of course, be left for the histolo- 
gist to explain the minute or microscopic structure of the various 
tissues. 

Relations of Structure to Function. — Function may be 
defined as the specific work of an organ or tissue of the body. An 
organ is a specialized structure whose function is some special 
kind of work. In order that any tissue or organ may perform its 
normal function it must itself be normal in its development, its 
growth, its cellular composition, and in its structural relations with 
other organs. The last of these requirements is probably most 
10 



GENERAL AND OSTEOPATHIC. 11 

essential because, if the structural relations are right, normal 
development, growth, etc., will follow. 

If, on the other hand, any abnormal structural relations exist 
these may affect the blood or nerve supply or in some other way 
interfere with its development, growth, or the functional activi- 
ties of its component cells, thus affecting the functions of the 
organ. It is well known that the functions of any individual 
structure depend not only on its own normal structural relations, 
but to some extent upon the functional activities of other struct- 
ures. If the heart, for example, fails to pump the necessary 
amount of blood to any certain organ or if the nerve supply for 
any reason is insufficient, thus rendering the regulation of its 
functional activities abnormal, that structure fails to perform its 
normal kind or amount of work. Since the various organs of the 
body bear certain functional relationships to each other, any per- 
version of the functions of one structure may materially interfere 
with the functions of other structures, and thus we have an example 
of the unity of body structures and their functions. 

This dependence of function upon structure may again be 
compared to the working of a machine. If at any time a certain 
mechanism fails in its proper adjustment the work of that part is 
impaired or lost, and in most cases the entire machine is value- 
less until this one part is repaired. 

Structure Depends upon Function. — In the above para- 
graphs it has been shown that normal function depends upon 
normal structure and now we must state the converse, viz., that 
normal structure is dependent upon normal function, which is also 
true. To illustrate we may use the example of the blacksmith's 
arm to show how cultivation of the function tends to develop 
and normalize structure, or on the other hand how, when one 
fails to take the necessary amount of exercise, his muscles atrophy 
and become weak. In future chapters the more complicated and 
intricate relations will be discussed which show these same prin- 
ciples. 

Certain laws of physics apply also to the body as well as to 
other mechanisms. The laws of conservation and transformation 



12 physiology: 

of energy, for example, hold good for the animal machine. The 
source of energy is the food and air used as fuel. It may be trans- 
formed, transferred, or lost, but cannot be created within the body. 
The efficiency of the body machine is much greater than that of 
other machines, but here again the efficiency depends upon the 
degree of perfection of its structural relations. 

Body Repair. — The body machine has one marked advan- 
tage over other machines and that is that it maintains its own 
repair shop. Certain cellular elements of the body, the red blood 
corpuscles, serve to replenish the various tissues with oxygen and 
the blood in this and other ways repairs tissue as it wears and also 
furnishes material for energy to its muscles and other working 
organs. The blood also carries other cells, the white blood cor- 
puscles, which may be called scavenger cells, whose function is to 
carry away waste and protect against the invasion of bacteria, etc. 

From the above paragraphs it may be seen that the body is an 
automatic machine in that it repairs its own wear and regulates its 
own work. Normal structure and structural relations mean 
normal functions and this stated in the converse, viz. , that normal 
function cannot result from abnormal relations, is the osteopathic 
theory of disease. Just so long as normal structural and func- 
tional relations of the body machine are normal the individual will 
show evidence of that phenomenon which we call life. 

Physiology may be defined as that branch of science which 
treats of the various changes and processes occuring in the animal 
organism during life. 

Physiological changes are those changes, whether physical 
or chemical in nature, which occur in the normal living body. 
The term metabolism is generally attached to these changes and 
usually applies to physiological chemical changes w T hich occur in 
the various tissues. Metabolism may be either constructive, a 
building or forming process, anabolism, or it may be destructive, 
a breaking-down process, catabolism. Changes anabolic in nature 
occur in tissue building, cell formation, etc., in which protein 
material from the foodstuffs, for example, is built into living tissue 
substance; and changes catabolic in nature occur in the destructive 



GENERAL AND OSTEOPATHIC. 13 

oxidation processes of certain foods, carbohydrates, fats, etc., 
the result of which is the liberation of heat and other forms of 
energy which yield power to do work. 

These changes occur in all living organisms, animals and 
plants, and are necessary for the life processes of the organisms. 
In the lower forms of life, such as the amceba, all necessary life 
processes can be effected in the one simple cell of which the animal 
consists. 

There are certain essential functions necessary to the life of 
every living animal, regardless of its scale of development. These 
are known as the essential physiological functions of protoplasm. 
They are metabolism, which has been defined; movement, by virtue 
of which animals are enabled to move or change their environ- 
mental conditions, which in case of the lowest forms consists of an 
amoeboid movement, by means of which the animal may adjust 
its body to new food supplies, etc.; the third function is growth, a 
process of continued constructive metabolism; fourth, reproduc- 
tion, the process by means of which the animal reproduces its 
kind; the fifth, irritability, or the quality of responding to a stim- 
ulus. A sixth is sometimes given, which is a specific one and refers 
to some function of a specialized or highly differentiated structure. 

In the higher forms of life these various functions are per- 
formed by organs highly differentiated and adapted for the per- 
formance of some one or more special functions. Movement in 
the higher forms, for example, is effected by the musculature, 
irritability by the system of nerves, etc. This differentiation 
of structures for the purpose of performing these special and sepa- 
rate functions enables the higher animals to do work and per- 
form the various life processes much more perfectly, and con- 
stitutes a plan of physiological division of labor. 

The Cell Theory. — Early in the eighteenth century the 
theory was advanced by Schleiden and Schwann, supported by 
other observers, that the cell constituted the histological basis 
of all animal structure. Since that time various workers in the 
biological sciences have developed this idea into a very explana- 



14 physiology: 

tory theory of all life processes, the main principles of which are 
discussed in the following paragraphs : 

1. The cell constitutes the anatomical and physiological 
unit of the organism, and the life processes of the individual 
organism are determined by the nature of the various cells which 
compose it. 

2. Anatomically the various cells have undergone various 
processes of differentiating changes during the phylogenetic evo- 
lution of the organism, and now in the higher forms of life these 
specially differentiated structures which have resulted have the 
power of performing specialized functions according to the nature 
of the structure. 

3. The cell is to the organ as the organ is to the body; that 
is, the functional activities of the organ depend upon the nature 
of the cells which compose it, just the same as the functional ac- 
tivities of the body as a whole depend upon the nature of its 
various organs. 

4. The unity of functional relationships of the body as a 
whole depends upon the completeness of the functional activities 
of its various organs, and in turn the unity of function of the 
organ depends upon the functional activities of its various cells. 

5. Every cell in the organ bears a certain functional rela- 
tionship to every other cell of that structure, every organ of the 
body bears certain functional relations to every other organ, and 
the maximum of perfection of the various functions of all cells 
and organs renders to the body as a whole the sum total of per- 
fect functional activity or health. 

6. By the physiological division of labor, then, all of the 
various structures have special functions to perform, and any 
one of these failing in its function may cause an unequal balance 
or perversion of function and the result is disease. 

Since normal function can be effected only by normal 
structure and since also normal structural relations must exist 
in all tissues, because of the inter-relations existing between the 
various structures, any perversion of structure may and usually 



GENERAL AND OSTEOPATHIC. 15 

will result in abnormal function, and this is the osteopathic 
theory of health and disease. 

General physiology is that branch of science which treats 
of the various functions of the living animal. Special physiology 
is a branch of general physiology which teaches the special functions 
of some specialized structure or structures. Human physiology 
refers to those physiological changes occurring in the human body. 
Cellular physiology refers to those physiological changes occurring 
in the cell. Osteopathic physiology is that branch of general 
physiology which considers especially the relations of structure 
and function and the unity of these combined functions. 



SECTION I 



THE BODY FLUIDS 



PART I 

PRINCIPLES OF GENERAL AND OSTEO 
PATHIC PHYSIOLOGY. 



CHAPTER I. 
BODY FLUIDS. 

In the lower forms of life the food of the single-celled animals 
is contained in the fluids in which they live, and likewise the body 
excreta of these simple forms is thrown off into and carried away 
by these fluids. The animal only needs to move a short distance 
to bring itself into relation with new food supplies in its surround- 
ing medium. As the animal body becomes more complex in the 
higher forms of life this method of supplying its cells with food and 
relieving them of their wastes becomes impossible, and there origi- 
nates a demand for a new structural system for supplying this 
function, and the demand is supplied by the bJood-vascular system. 
This system, which consists of closed tabes in which the body fluids 
circulate, serves the functions of carrying food supplies to the va 
rious tissues, removing the waste products of cell metabolism, and 
other functions to be discussed later. These fluids consist of blood 
and lymph and the serums from these fluids, which are found in the 
various extravascular spaces in the body. In case of the blood, 
it is first pumped from the heart through the arteries and into 
the thin-walled capillaries, where it comes in almost direct con- 
tact with the cells of the various tissues. Here certain contents 
of the blood are given up to these tissues and certain wastes from 



20 PHYSIOLOGY : 

the tissue cells are emptied back into the blood stream. In some 
instances., as in the case of those vessels which supply the intes- 
tinal tract, food materials are taken up by the blood and carried 
to other tissues where they are needed or carried to some store- 
house, as in case of the liver, and kept for future use. After the 
blood leaves the capillaries it passes into the veins and is carried 
back to the heart to begin its circulation anew. 

Not all of the tissue wastes are emptied back into the blood 
stream. Some go by another route, the lymph channels. The 
lymph vessels are small, thin-walled tubes containing valves to 
prevent back-flow, and serving the function of carrying the extra- 
vascular fluids back to the veins. 

BLOOD. 

General Properties. — Blood has an average specific gravity 
of 1.055, varying under certain conditions within very narrow 
limits. The specific gravity of blood is best determined by com- 
paring with liquids of known density. A mixture of chloroform 
and benzol may be so prepared that the solution has a specific 
gravity of 1.055. A drop of fresh blood is allowed to fall into this 
solution. If it sinks it is known to be heavier, and if it floats on 
the surface it is known to be lighter than the test fluid. There 
are certain instruments sometimes used for this purpose, but 
they are not of any great value in practical determinations. 
The specific gravity of the blood varies slightly with age, sex, 
time of day (being slightly higher at night), etc., but this is of no 
practical consideration. Blood is normally neutral in reaction 
when tested with phenolpthalein as an indicator, bub may be 
slightly alkaline when tested with litmus. 

The color of blood varies from that of scarlet in the arteries 
to purplish in the veins. The presence of oxyhemoglobin in arte- 
rial blood gives the scarlet color, and the intensity of the color 
varies with the amount of oxyhemoglobin. The oxygen of the 
hemoglobin is given up to the tissues as the blQod passes through 
the capillaries; thus the change of color in the veins. 



GENERAL AND OSTEOPATHIC. 21 

CONSTITUENTS OF BLOOD. 

Plasma is the liquid portion of the blood in which the cor- 
puscles float. Its specific gravity varies from 1.026 to 1.030. 
Serum is the liquid portion of the blood after coagulation, and 
represents the plasma minus fibrinogen. The clot consists of 
corpuscles and fibiin. Stewart compares these as follows: 

Plasma + fibrin (ogen) = serum. 

Corpuscles -\- fibrin = clot 

Plasma + corpuscles = serum -f- clot = blood. 

Red Blood Corpuscles. — The red blood corpuscles or 
erythrocytes are discal, biconcave bodies, 7.5 micra in diameter, 
2.5 micra in thickness at the periphery, and from 1 to 2 micra 
thick at their mid-portion. The normal number of erythrocytes 
for the adult male is 5,000,000 per cubic millimeter and for females 
4,500,000 per cubic millimeter. 

Physiological Variation in Number. — The number of 
red corpuscles varies with certain conditions, as follows: 1. The 
number varies inversely with age, i. e., the greatest number being 
found in the foetus and gradually decreasing during the life of the 
individual; 2. the number is decreased in females, being about 
4,500,000 per cubic millimeter; 3. the number is decreased after 
meals; 4. the number is slightly increased during menstruation, 
and 5. is diminished during pregnancy; 6. the number is in- 
creased in those living in high altitudes, and in those going from 
low to high altitudes the number may be increased to as many as 
7,000,000 or 8,000,000 and the change occurs quickly, being noted 
within a few (twelve to forty-eight) hours. This change seems to 
occur in answer to a demand of function, there being a call on the 
system for a greater oxygen-carrying power, due to the lessened 
amount of oxygen in the air. 

The function of erythrocytes is to carry oxygen from the 
lungs where it is taken from the inspired air, and to carry it to the 
cells of the various tissues. The oxygen is carried by means of 
the hemoglobin contained in the corpuscles. Erythrocytes con- 
sist of stroma, which is the structural part; certain salts, such as 



22 PHYSIOLOGY : 

lecithin and cholesterin; water, and hemoglobin, the latter being 
its chief functional constituent. The hemoglobin constitutes 
about 32% by weight of the erythrocyte, and 90% of the total 
solids. It is not known how the hemoglobin is held in the corpuscle, 
but it is believed to be held in some way by the stroma. Whether 
the lecithin or cholesterin take any part in the specific functions 
of the corpuscles is not known. According to Starling the 
red blood corpuscles constitute about 50% of the total mass of 
the blood. These small bodies are flexible and elastic, and readily 
return to their original form when distorted by pressure. The 
size and shape of the corpuscles vary with different animals. In 
nearly all mammals they have the shape described above. In 
vertebrates below the mammals and other animals still lower in 
the scale of development the red corpuscles are nucleated and 
biconvex, but normally they have no nuclei in the human. In 
camels they resemble the human type, but are oval instead of 
circular. During the first few weeks of fcetal life; after the loss 
of a quantity of blood by hemorrhage; in certain blood diseases, 
and before they are passed into the blood stream from their source 
of formation, the red blood corpuscles of the human may be found 
to contain nuclei. Nucleated red blood corpuscles or normoblasts 
are never found in normal blood of the normal human individual 
after birth. The total surface area of all of the blood corpuscles 
of the blood is about "1500 times the surface of the body 
itself'' (Starling). This fact shows the great oxygen -carrying 
capacity of these corpuscles. 

Red blood corpuscles are continually being formed from 
erythroblasts, the forerunners of the red blood corpuscles contained 
in the red bone marrow of the epiphyses, and after the develop- 
ment is complete and they have lost their nuclei they are taken up 
by the blood stream and carried through the circulatory system. 
In the bone marrow, where the vessels are dilated and the capil- 
laries are very thin-walled, these small bodies may easily enter 
the vessels. The red bone marrow is the chief and possibly the 
only hematopoietic (blood-forming) structure in the adult, but 
the liver and spleen are generally considered as embryonic hema- 



GENERAL AND OSTEOPATHIC. 23 

topoietic structures, having to do with the formation of the red 
blood cells during early embryonic and fcetal life. 

Erythrocytes are constantly undergoing degeneration. It is 
not known how long they exist in the blood stream as functional 
structures. The products of disintegration as they degenerate 
are probably taken up and carried away by the leucocytes. In 
the spleen and in the hemolymph glands certain large phagocytic 
cells may be found which often contain ingested parts of disinte- 
grated erythrocytes, and it is generally supposed that these struct- 
ures have something to do with the fate of the useless red blood 
cells. The hemoglobin of the red corpuscles is taken up by the 
liver cells and excreted in the bile. 

HEMOGLOBIN. 

Chemically, hemoglobin is a complex protein consisting of 
carbon, hydrogen, nitrogen, oxygen, sulphur, and iron. The 
molecular formula has not been positively determined, but it is 
known that the molecule is very large. Hemoglobin may be readily 
broken down by the action of heat or by the addition of alkalis 
or acids, forming two compounds, hematin and globin, and other 
undetermined substances. The globin constitutes the greater 
part of the molecule (about 90%) and the hematin constitutes a 
much smaller part (about 4%) of the molecule. If hemoglobin 
be decomposed in the absence of oxygen the products are hemo- 
chromogen and globin instead of hematin and globin. 

Hemoglobin fo^ms an important constituent of the blood 
of all vertebrate and many invertebrate animals, and its function, 
as already stated, is that of carrying oxygen. Hemoglobin con- 
stitutes about 14% by weight of human blood, i. e., 100 grams of 
blood would contain 14 grams of hemoglobin. "It is estimated 
that in the blood of a man weighing 68 kilograms there are con- 
tained about 500 to 700 grams of hemoglobin, which is distrib- 
uted among some 25,000,000,000,000 of corpuscles, giving a total 
superficial area of about 3200 square meters." (Howell.) From 
this statement and the discussion above relative to the surface area 



24 PHYSIOLOGY I 

of the red corpuscles, it may be seen that a very great area is 
exposed for the purpose of absorption of oxygen in the lung area 
and the distribution of oxygen to the tissues. 

Hemoglobin Compounds. — In the lungs hemoglobin read- 
ily unites with oxygen from the inspired air, forming a definite 
chemical compound, oxyhemoglobin. This gives to blood its 
characteristic scarlet color. It may be shown experimentally 
by passing air through freshly drawn venous blood that the color 
may be made to change to scarlet. It is probable that each mole- 
cule of hemoglobin unites with one molecule of oxygen in the 
formation of oxyhemoglobin. The compound thus formed is 
not a stable one, but liberates the oxygen readily when in relation 
with tissues whose cells are in need of oxygen. The advantage of 
such a weak combination may readily be seen, for if the oxygen 
united in such a way as to form a stable compound, the oxygen 
could not easily be separated for the supply of tissue cells. 

With many other substances such as carbon monoxide, oxides 
of nitrogen, etc., hemoglobin forms stable compounds, one mole- 
cule of the hemoglobin uniting with one molecule of carbon mon- 
oxide. Because of the formation of this stable compound and be- 
cause the hemoglobin is thus rendered unable to unite with oxygen 
for the purpose of carrying it to tissue cells, the carbon monoxide 
causes asphyxia or suffocation for the lack of oxygen. Asphyxia 
from gas is due to this cause, the carbon monoxide of the gas 
rendering the corpuscles unable to carry oxygen. 

Iron forms an important constituent of hemoglobin, and 
while it is present in small quantities (about .33%) this amount is 
so constant that an estimation of hemoglobin may be made by 
determining the amount of iron. The function of iron is that of 
assisting the hemoglobin in combining with oxygen. 

Hemoglobin of the blood may be estimated quantitatively 
by certain instruments (hemoglobinometers), but these are not 
so practical as the colorimetric method, which is done by com- 
paring the color of a blood stain made by placing a drop of freshly 
drawn blood upon a piece of absorbent paper and comparing this 
with certain standard colors, the percentages of which are marked 



GENERAL AND OSTEOPATHIC. 25 

on the scale. The Tallqvist scale is the one most commonly used 
in clinical work. 

Hemoglobin Crystals. — By adding a few drops of ether to 
freshly drawn blood contained in a test tube and shaking the 
mixture until the blood is hemolized and then quickly cooling with 
ice, the crystals may be deposited. The crystals may be observed 
by placing some of the sediment on a slide and examining with 
the microscope. Oxyhemoglobin and hemoglobin both readily 
crystallize and the forms of the crystals are characteristic of the 
species, i. e., the form, shape, and size of the crystals vary in differ- 
ent animals. The difference in the form of the crystals is prob- 
ably due to some difference in the molecular arrangement of the 
hemoglobin of the particular species from which it comes. 

Hemolysis. — The process of separation of the hemoglobin 
from the red corpuscle so that it may pass into solution in the 
plasma is known as hemolysis. Blood when so changed is known 
as hemolyzed or laky blood, and substances which have the power 
of producing a hemolysis are known as hemolytic agents, e. g., 
bile salts, chloroform, alcohol, ether, various alkaline salts, etc. 
A great many substances may act as hemolytic agents when brought 
into the presence of normal blood. Anything which diminishes 
the osmotic pressure of the plasma, such as the addition of an ex- 
cess of water, will cause hemolysis. For this reason when it is 
necessary to inject liquid into the system, a solution of 9% sodium 
chloride (physiological normal salt solution) is used. It may be 
that the cause of hemolysis in case of reduction of osmotic pressure 
by the addition of hypotonic solutions is the comparatively in- 
creased pressure within the corpuscle, causing it to rupture and 
discharge its contained hemoglobin. Whether the above explana- 
tion is correct for the cause of hemolysis in case of dilution or re- 
duction of the density of the plasma has not been shown, but that 
hemolysis may be effected in other ways is evident. There are 
many toxic substances, such as snake venom, products of bacterial 
action, or certain contents of. sera of other animals, that may 
cause hemolysis when injected into the animal or by tests made 
upon drawn blood in very small quantities, in which case the re- 
duction of the plasma could play no part. 



26 physiology: 

Hemolysins. — The term hemolysin is applied to those sub- 
stances produced by tissues of the body and contained in the body 
fluids, whose function is that of reacting against blood of other 
animals causing hemolysis of the corpuscles. The first valuable 
work along this line, according to McFarland, was the researches 
of "Belfante and Carboune" who "showed that if horses were 
injected with red corpuscles of rabbits, the serum thereafter ob- 
tained from the horses would be toxic for rabbits." Many other 
workers have shown other similar reactions. Bordet has shown 
that guinea pigs, after having been injected several times with 
from three to five cubic centimeters of defibrinated rabbit's blood, 
developed something in their serum which had the power of 
hemolyzing rabbit's blood. Ehrlich and others have since shown 
that there are certain substances produced by the tissues of one 
animal, when injected with blood from another, which gives to 
the blood of the first animal the power of effecting this chemico- 
physiological change in the corpuscles of the second animal. These 
substances (amboceptors) which are one class of antibodies, are 
not normally present in blood in sufficient quantity to produce any 
marked effect, but their formation may be increased by the pres- 
ence of some toxic substance in the blood known as antigen. When, 
then, the amboceptor substance is formed in sufficient quantity, 
it may unite with another substance (complement) which is found 
normally preseut in blood, and these two then unite with the 
corpuscle, causing hemolysis. The reaction may be represented 
diagrammatically as follows: 



2 <z^z> y 



letting 1 represent the blood corpuscle; 2 the amboceptor and 3 
the complement. When 2 is produced iri sufficient quantity to 
cause the union of 1 and 3 as 



the result would be hemolysis of the red blood corpuscles. 



GENERAL AND OSTEOPATHIC. 27 

White Blood Corpuscles — Leucocytes. — These blood 
corpuscles differ from the erythrocytes in many respects both in 
morphology and function. Leucocytes are living body cells in 
every way. They have one or more nuclei, which may be seen 
under the microscope if acetic acid be added or proper stains are 
used. They vary in number from 5,000 to 7,000 per cubic m. m. 
in human blood and vary in size from five to fifteen micra in diam- 
eter. Slight normal variations in the number of leucocytes may 
occur from exercise, digestive changes, pregnancy, etc., and ab- 
normal variations occur in certain disease conditions. Any 
marked increase in the leucocyte count is known as leucocytosis 
and commonly occurs in the acute infectious fevers, in which the 
number may be increased to 30,000 or 40,000. Any marked 
decrease in the normal number is known as leucopenia and occurs 
in certain blood diseases, the anemias, and in some other condi- 
tions. 

Classification. — Many different methods of classification 
of leucocytes have been used, but most physiologists now prefer 
the system as used by Ehrlich and Engel, who classify all white or 
colorless blood cells into two general divisions and these into 
subdivisions, as shown by the following table. 
I 1 Lymphocytes. 

I 2 General characteristics: 

l 3 Possessed with only slight amoeboid movement, prob- 
ably not motile. 
2 3 Have no granules. 

3 3 Originate from lymph glands and lymphoid tissue. 
2 2 Classes: 
l 3 Small. 

I 4 Characteristics: 

l 5 Large, symmetrical nucleus, located in center 

of cell. 
2 5 About 7.5 micra in diameter. 
3 5 Proportionately small amount of cytoplasm, 

not granular. 
4 5 Constitute from 20% to 25% of the total 
number of white corpuscles. 



28 physiology : 

2 3 Large. 

I 4 Characteristics: 

l 5 Nucleus not centrally located, smaller in 

proportion to cell. 
2 5 Size, from 15 to 20 micra in diameter. 
3 5 Proportionately larger amount of cytoplasm, 

not granular. 
4 5 Constitute about 1% of the total number of 
white blood cells. 
2 1 Leucocytes. 

I 2 General Characteristics: 

l 3 Marked power of ameboid movement. 
2 3 Granules present in cytoplasm. 
3 3 Originate from yellow bone marrow. 
2 2 Classes. 

I 3 Transitional forms. 
I 4 Characteristics: 

l 5 One large, lobulated nucleus. 
2 5 Size, 12 to 15 micra. 

3 5 Proportionately large amount of granular 

cytoplasm. Granules stain with neutral 

dyes and are therefore called neutrophilic 

granules. 

4 5 Constitute from 3% to 10% of total number 

of white cells. 
5 5 These cells are thought to represent a trans- 
itional stage between the large lympho- 
cytes, but this is not positively established. 
2 3 Polymorphonuclear forms. 
I 4 Characteristics: 

l 5 Nucleus segmented into distinct lobes. 
2 5 Size, 10 to 12 micra (Stewart). 

Cytoplasm granules and stain with neutral 

dyes. 
Constitute from 60% to 75% of the total 
number of white cells. 



,5 



GENERAL AND OSTEOPATHIC. 29 

5 5 These cells are very motile and highly 

phagocytic. 
6 5 Eosinophiles or eosinophilic leucocytes, a 
sub-group of the polynuclears, are similar 
to the above, differing in that they have 
larger granules, which stain with eosia. 
Size, 12 to 15 micra in diameter (Stewart). 
3 3 Mast Cells. 

I 4 Characteristics: 

l 5 This group differs from the polynuclear in 
that their granules stain with the basic 
dyes. They constitute Jess than 1% of 
total number of white cells. The baso- 
phils are about 10 micra in diameter. 
(Stewart). 
Functions of Leucocytes. — Leucocytes may be called the 
wandering cells of the body. They have the property of being 
able to pass through the capillary walls and in this way come in 
immediate contact with the various tissue cells. Because of this 
ability those which are possessed with the greatest ameboid move- 
ment may work their way to any tissue, where, in case of inflam- 
mation, they are attracted to the part probably by a specific 
attraction known as chemotaxis. 

1. These cells have the property of ingesting foreign sub- 
stances and by this phagocytic action serve to destroy bacteria, 
products of tissue disintegration, etc., and may be properly called 
the scavengers of the body. This property of phagocytosis, which 
was discovered principally by the researches of Metschnikoff 
(1892) has been shown to be a method of body protection against 
invading bacteria. These cells also have the property of secreting 
certain substances known as bacteriolysins, which are both bac- 
tericidal and antiseptic to toxins of bacteria. The recent re- 
searches of Wright have shown that the leucocytes depend for 
their phagocytic activity upon other substances known as opsonins 
(taken from opsono, and meaning "I prepare food for")- It 
may be thought of as a kind of bacterial sauce, in that it sensitizes 



30 physiology : 

the bacteria and renders them .more easily ingested by the leu- 
cocytes. There are many other such substances formed in the 
body by various structures, which protect in various ways against 
various kinds of poisonous substances in the blood and other body 
fluids. It has been shown that, if an animal is experimentally 
inoculated with a small quantity of bacteria the formation of these 
antibodies is increased, and that, if the inoculation be repeated 
several times, the antibodies in the body fluids will continue to be 
increased until a condition of immunity or complete resistance is 
established. This is another example of a physiological response 
to a demand for a function or a method of development of a pro- 
tective adaptation, and is known as a " biological reaction." 

2. Leucocytes take part in blood coagulation, as will be dis- 
cussed later. 

3. By their constant disintegration and dissolution in the 
blood stream they assist in maintaining the normal protein com- 
position of the blood. 

4. They probably aid in the absorption of fats in the in- 
testine, and they assist in some way in the absorption of peptones. 

Blood Plates. — These small bodies present in blood vary in 
size from particles so small that they can scarcely be detected with 
the microscope to about five microns in diameter. They are 
usually circular in form and homogeneous in appearance. These 
bodies readily disintegrate when removed from the blood. There 
is so little known about these bodies as regards their origin, func- 
tion, or relation to other blood elements, that little can be said. 
They probably take part in the process of coagulation by forming 
prothrombin, as will be discussed under that subject. It is not 
known whether they are distinct cells, maintaining a separate 
and independent existence, or whether they represent disintegra- 
tion products of the blood cells. The probable normal number of 
blood plates is about 300,000 per cubic m. m., which is said to be 
markedly reduced in disease affecting other blood corpuscles. 



CHAPTER II. 



CHEMICAL PROPERTIES OF BLOOD. 



Because of the relation of the blood to the body and its func- 
tions in supplying tissue with good material and relieving the cells 
of their waste, it may readily be seen that the blood will necessarily 
contain a great variety of chemical constituents. The chief 
constituents of blood are water, oxygen, carbon dioxide and ni- 
trogen in various forms. 

The following table taken from Howell gives Abderhalden's 
results of quantitative chemical analysis of blood: 







1000 Parts, by 


1000 Parts, by 


1000 Parts, by 






Weight, of Blood 


Weight, of Serum 


Weight, of Corpus 






Contain 


Contain 


cles Contain 


Water 




810.05 


923 . 98 


644.26 


Solids 




189.95 


76.02 


355 . 75 


Hemoglobin 




133.4 




327.52 


Protein 




39.68 


60.14 


9.918 


Sugar 




1.09 


1.82 




Cholesterin 




1.298 


0.709 


2.155 


Lecithin 




2.052 


1.699 


2.568 


Fat 




0.631 


1.051 




Fatty acids 




0.759 


1.221 


0.088 


Phosphoric •< 


icid: 








as nuclein 


0.054 


0.016 


0.110 


Na 2 




3.675 


4.263 


2.821 


K 2 




0.251 


0.226 


0.289 


Fe 2 3 




0.641 




1.573 


CaO 




0.062 


0.113 




MgO 




0.052 


0.040 


0.071 


CI 




2.935 


4.023 


1.352 


PaOs 




0.809 


0.242 


1.635 


Inorganic : 


P2O5 


0.576 


0.080 


1.298 



Blood Proteins. — Three proteins are present in blood, viz., 
fibrinogen, serum-globulin or paraglobulin, and serum albumin. 

The chemical properties of .these proteins may be found dis- 
cussed in texts on physiological chemistry. Their functions only 
will be given here. 



32 PHYSIOLOGY I 

Fibrinogen is always present in blood and lymph, but only 
in small quantities (.2% to .4%). Since this protein takes an ac- 
tive part in the process of coagulation, entering into the formation 
of fibrin, it is not found in the serum. The functions of fibrinogen 
other than its property of assisting in blood coagulation are not 
definitely known. The origin of this protein is also unknown., 
but there is some reason to believe it may be formed in the liver. 

Serum-globulin is a normal constituent of blood, lymph, and 
in all body exudates, normal or pathologiclal. Paraglobulin is 
present in human blood plasma in quantities varying from 3% to 
3.5%, and is also present in blood serum in even greater quantities. 
The source of this protein is also not well understood. It comes 
either from the absorbed proteins from the digestive tract or the 
disintegration of leucocytes. 

Serum-albumin like serum-globulin is present in blood, 
lymph, extravascular lymph, and all exudates, norma] or path- 
ological. Human blood contains from 3% to 5% of this protein. 
It originates from the digested proteins of the intestinal tract, 
after a series of complex changes from peptones, proteoses, etc. 
Serum-albumin is probably the chief functional protein in tissue 
building. 

BLOOD COAGULATION. 

If blood is allowed to escape from the vessels a change is 
noted in a short time, characterized by the formation of a solid 
mass from which a straw-colored fluid, the serum, is expressed by 
contraction of the solid mass or clot. This process is known as 
coagulation. The clot consists of fibrin and red and non-motile 
leucocytes. The fibrin is formed from fibrinogen of blood plasma. 
If freshly drawn blood be whipped rapidly with twigs or a glass 
rod the fibrin is deposited on the rod, thus preventing clotting. 
The remaining serum (whipped blood) contains the corpuscles, 
and if entirely defibrinated will not coagulate. The process of 
coagulation may be observed under the microscope by placing a 
drop of fresh blood on a glass slide and covering it with a cover 
slip or by making a hanging-drop preparation. After some minutes 



GENERAL AND OSTEOPATHIC. 33 

a careful examination will reveal the minute fibrin threads among 
the corpuscles. 

Coagulation — How Caused. — A great many theories of 
blood coagulation have been advanced, but it is considered best 
to leave these to the history of physiology rather than expect the 
student to learn them now. The process of clotting is caused by 
fibrin, which results from the action of thrombin upon fibrinogen. 
The various theories are concerned with the explanation of how 
this change is effected. The modern theory explains this by stat- 
ing that there is a substance (prothrombin) in the blood, which 
results from the degeneration of leucocytes and blood plates. 
This prothrombin, by the action of calcium salts, is changed to 
thrombin and the thrombin reacts with fibrinogen, forming fibrin. 
The fibrin produces the clot as stated above, and the degenera- 
tion of this clotted material continues to form more prothrombin, 
and thus the process is continued. 

By some authorities it is believed that the thrombin is present 
in the blood in an inactive form known as thrombogen, and that 
this must be changed to an active form by the action of calcium 
salts and an organic substance supposed to be thrombokinase. 
This kinase is supposed to be produced by certain tissue cells and 
cellular elements of the blood and a necessary factor in blood 
coagulation. It is assumed that in case of injury causing bleeding 
on exposure the blood cells and plates and possibly the injured 
tissues produce thrombokinase, which in association with the cal- 
cium salts causes coagulation, as explained above. Thrombokinase 
has never been isolated nor has it ever been demonstrated that an 
organic kinase is necessary in addition to the calcium for the 
activation of the disintegrated cellular elements, the prothrombin. 
Howell and his co-workers have explained that activation of 
prothrombin is not necessary, and that the blood is kept liquid in 
the vessels by the action of a substance known as antithrombin, 
which prevents the calcium from (activating) changing the pro- 
thrombin to thrombin. They assume that when blood is shed or 
tissue is injured another substance is produced which neutralizes 
the antithrombin, and the process of formation of thrombin and 



34 



physiology: 



fibrin continues as explained above. The following diagram serves 
to illustrate the general plan of blood coagulation: 



Fibrinogen 
Normally present in blood 



Fibrinogen . 



Cellular elements which result from the 
disintegration of leucocytes, blood plates, 
etc., form 

I 

Prothrombin (throbogen) . 

I 

Prothrombin plus calcium salts and possibly 
some unknown substance forms 

V 

. plus Thrombin 



-> Fibrin <r 



Clot 



Fibrinogen . 



, plus . 



Clot, by disintegration forms more 
prothrombin -\- calcium salts = 

. . . Thrombin 



Fibrin 4- 



By this process a continuation of the 
clot-forming process is effected. 

The clotting time of blood varies with certain conditions, as 
follows : There is an individual variation for different persons, the 
cause of which is not well understood. Because of this fact, since 
clotting prevents loss of blood by hemorrhage, those individuals 
in whom the blood does not clot readily are often prone to excessive 
bleeding from the slightest injury, the condition being known as 
hemophilia. At room temperature the blood begins to coagulate 
in from five to ten minutes after it is drawn, but complete coagula- 
tion does not occur for several hours (12 to 48). Cooling increases 
the clotting time, and heating to 60° C. coagulates the fibrinogen 
and prevents clotting. 



GENERAL AND OSTEOPATHIC. 35 

Human blood is affected as regards its clotting time by certain 
disease conditions. In the infectious fevers, for example, the 
clotting time is usually greatly increased. 

Methods of Increasing Coagulation. — In cases of hemor- 
rhage, hemophilia, etc., it may become necessary to hasten the 
process of clotting: 1. By the application of heat or cold packs 
to the place of injury, the blood may be made to clot more quickly 
and thus stop the bleeding; 2. by the application of any sub- 
stance such as a sponge or a piece of gauze, which increases the 
surface area of the blood exposed and usually is sufficient if the 
wound is not large; 3. certain chemical substances, e. g., thrombin 
or tissue extracts, may be of use in case of hemmorrhage. Gelatin 
injected hypodermically is one of the most common methods of 
controlling hemorrhage. 

Methods of Preventing Clotting. — 1. By quickly cooling 
freshly drawn blood to a temperature of 0° C. ; or nearly so, it 
may be kept liquid for an indefinite length of time; 2. If blood be 
carefully drawn from an injured vessel into a dust-free and dust- 
proof, paraffin-lined vessel, clotting does not occur for several 
hours; 3. there are many chemical solutions, such as magnesium 
sulphate 25%, sodium sulphate (a half saturated solution), which 
prevent clotting, sodium oxalate, sodium citrate (10%), and some 
other similar chemicals prevent clotting by decalcification of the 
blood; 4. the injection of peptone plasma, which is prepared 
from the blood of animals previously injected with peptone solu- 
tion, retards blood coagulation; 5. the injection of leech extract 
(hirudin plasma) also retards coagulation. 

Intravascular Clotting. — It has been repeatedly shown that 
normal blood will not coagulate in a normal, uninjured blood vessel. 
This may be shown by ligating a large vein in two places in a liv- 
ing animal. The blood contained between the ligatures will not 
clot for several days if no injury is done to the vein. This is ex- 
plained by several possible theories : 1 . That thrombin is not pres- 
ent in normal blood in the active- form in sufficient quantities to 
cause clotting; 2. thrombokinase is not present; 3. cellular 
elements from tissue disintegration are not formed in sufficient 



36 PHYSIOLOGY : 

amounts, i. e., their formation is only gradual and therefore the 
prothrombin resulting from degenerations is not sufficiently active 
to form thrombin. In case of injury the tissue extractives from 
the injured tissue and prothrombin are deposited quickly; 4. 
the theory of the existence of a substance known as antithrombin 
which prevents the action of tissue extracts, etc., is supported 
by the fact that the injection of tissue extracts does not cause 
intravascular clotting. It is thought that leech extract, peptone 
plasma, etc., mentioned above, resemble antithrombin in that 
they counteract or restrain the action of thrombin. Foreign 
material of any kind, such as dust particles in air or air itself, 
may cause clotting in the blood vessels. It may be that these 
substances cause the formation of disintegration products — pro- 
thrombin, thrombin, etc. — and thus effect blood coagulation. The 
same process may result from any injury to the inner coat of the 
vessels. Certain chemical substances — solutions of calcium salts — 
may, when injected, cause intravascular clotting. 

QUANTITY AND DISTRIBUTION OF BLOOD. 

The total quantity of blood in the body is estimated to be 
about 7.7% of the body weight. Various methods have been 
used for determination, but in the human it is not an easy task. 
Bischoff has determined the quantity of blood of several guillotined 
criminals, with the results as given above. At this percentage, 
a man weighing 150 pounds would have about 11.5 pounds, or 
5 kilograms. Of this amount, as has been shown by experimental 
work on dogs, about half of the blood can be lost by hemorrhage, 
and if the animal is properly cared for, recovery will result. 
I have seen complete recovery result in a dog weighing 60 pounds, 
after drawing more than a liter of blood. 

Blood transfusion is the process of transferring blood from 
one animal to another. It has been used to some extent clinically 
for the support of a patient undergoing a surgical operation, but 
is little used because of certain dangers which may result. 

It is usually considered that if the blood of one species be 



GENERAL AND OSTEOPATHIC. 37 

transfused into the blood stream of another species the result 
will be death to the second animal, the cause being due to hemolysis. 
The results of such transfusion depend upon several conditions, 
such as the quantity of blood transfused; the method employed; 
the condition of the animal from which the blood is taken, etc. 
In some cases a very small amount of blood will cause hemolysis, 
but if the operation is done in such a way as to prevent clotting, or 
if defibrinated blood be used, the result is not fatal in animals of 
the same species. In some cases blood transfused from animals 
of one species into the veins of animals of other species is not 
followed by fatal results. If, for example, dog blood is transfused 
into cats, no evil effect follows, nor is cat blood fatal to dogs. 
This, however, is not generally true, for in many instances the 
transfusion of small quantities of the blood of one animal into 
another produces hemolysis. (See hemolysins.) 

In those cases in which blood transfusion may safely be 
practiced, such as from one kind of dog to another or from dog to 
cat, a short period of time is usually necessary for the animal 
to become normal again, but in some instances the operation is 
followed by almost no noticeable change. A great many physio- 
logical principles have been learned concerning circulation and 
blood changes by methods of blood transfusion, such as the effects 
of antibodies, etc., but this belongs under another heading. 

Regulation of the Quantity of Blood. — The circulation 
of the blood was discovered by Harvey in 1628. This opened the 
way for further research, and probably no other subject has under- 
gone as much variation in theory since that time as has the science 
of physiology. It is even yet doubtful if we should call it a sepa- 
rate science, as comparatively so little is known. It was formerly 
believed that if an individual lost as much as a few ounces of blood, 
this was almost fatal. Then came the bleeding era, when for 
almost any abnormal condition the patient was relieved of a quan- 
tity of blood, but almost nothing was actually known regarding 
the physiology of blood-letting. It is now well known that the 
body machine has a method by means of which the proper quan- 
tity of all body fluids is regulated, and there is very seldom if ever 
an excuse for bleeding. 



38 PHYSIOLOGY : 

The kidneys, skin, and other excretory organs, the physiology 
of which is to be given later, so regulate the quantity of blood in 
the body that the proper amount is maintained at all times. If, 
as in case of the loss of a quantity of blood by hemorrhage, any 
great amount is lost — from a pint to a quart or more — there are 
symptoms of collapse, and blood transfusion may be practiced. 
The use of physiological salt solution injected intravenously, 
subcutaneously , or per rectum, as the condition of the case demands, 
is usually as effective and always much safer than blood trans- 
fusion. This may be shown experimentally by bleeding an animal 
until the pulse is very faintly felt, and slowly injecting the same 
quantity of normal salt solution as blood removed, or until the 
pulse is full and the pressure is normal. Such animals will show 
symptoms of weakness until complete regeneration of the original 
amount of blood elements has occurred, which requires from one 
to three weeks in the dog. 

Distribution of Blood. — Blood distribution is determined 
by the functional need of the various structures supplied. The 
heart, lungs, and great vessels contain one-fourth ; the liver, one- 
fourth; the resting muscles, one-fourth, and the remaining one- 
fourth is distributed to the other tissues of the body. 

It may readily be seen that there is a functional demand for 
a large quantity of blood to be constantly supplied to the lungs, 
that the proper oxygenation may be effected. The functional 
demand of the liver will be better understood after the functions 
of the liver are noted. In the embryo and f cetus the liver performs 
an important function as a blood-forming organ, and grows ex- 
cessively large in proportion to other body parts. After birth the 
liver has many important functions, such as storing glycgoen, 
detoxication of the blood, etc., which demand a liberal blood 
supply. 

Resting muscle also demands a good blood supply for the 
restoration of its glycogen and oxygen after functional activity 
(see sources of muscle energy) . It may therefore be seen that 
the demand of function and the development of structural 
relations to meet this demand are the determining factors in the 
distribution of blood in the body. 



CHAPTER III. 
LYMPH. 

General Properties. — Lymph is a colorless or slightly yel- 
lowish fluid except after meals, when it is cloudy or milky because 
of the presence of varying quantities of finely divided fats, the 
fat constituting the basic part of the chyle, which is the substance 
taken up by the lacteals from the intestine during absorption. 
Lymph varies in its composition, according to the location in 
the body from which it is obtained. Lymph from the thoracic 
duct varies according to conditions of the animal, the length of 
time since it has been fed, and the kind of food eaten. If the 
animal has recently had a meal of fats the lymph is rich in finely 
divided fat. It is slightly alkaline in reaction and has a specific 
gravity of about 1.915. It clots upon standing, producing a 
colorless clot of fibrin and serum very similar to that of blood. 
Lymph from the thoracic duct contains about 6% of solid matter, 
which consists chiefly of proteins, fibrinogen, paraglobulin and 
serum albumin. The inorganic salts are about the same in quality 
and amount as in blood. 

Where Found. — Lymph is found in the lymph vessels, in 
extravascular spaces — all tissues of the body being thoroughly 
bathed in this fluid — and it is also found in the various vascular 
sacs, where it performs functions of protection and lubrication, 
and furnishes in some cases nourishment to the surrounding struc- 
tures. This type of extravascular lymph, such as pericardial 
fluid, synovial fluid, cerebro-spinal fluid, aqueous humor, pleuritic 
fluid, etc., varies somewhat in its composition from vascular lymph. 

Origin and Formation of Lymph. — The fluid of the lymph 
and the salts come from the plasma of the blood by a process of 
filtration or secretion, and this is not as yet known There are 
good reasons for both theories, some of which will be briefly given: 

39 



40 PHYSIOLOGY : 

The secretion theory is supported by the following evidence: 
There are certain substances known as lymphagogues, which 
when injected into the blood stream cause an increase in the forma- 
tion of lymph. Lymphagogues are generally divided into two 
classes: Those of the first class, such as peptone; extracts of leaches 
(head and liver); extracts of muscles of crayfish; albumin, etc., 
and those of the second class, the crystalloids, such as solutions of 
salt, sugar, etc. It has been shown by Starling that the intra- 
venous injection of lymphagogues of the second class produces 
an increase in the formation of lymph by attracting water from the 
tissues, causing a hydrsemic plethora, without increasing the 
arterial pressure. 

The fact that' lymphagogues increase the formation of lymph 
was considered by Heidenhain, the chief supporter of the secretion 
theory, as the strongest argument in its favor. 

The theory of filtration is supported by the fact that certain 
conditions which increase the pressure in the capillaries are followed 
by an increase in the formation of lymph. This has been demon- 
strated by ligation of the vena cava, which, since the flow of blood 
is prevented, increases the pressure and the operation is followed 
by an increase in lymph formation. By the injection of large 
quantities of normal salt solution, thus increasing the blood pres- 
sure, the lymph flow is increased. This argument is met by 
the adherents to the secretion theory by the fact that secretagogues 
cause an increase in the formation of lymph without causing an 
increase in the blood pressure. 

We may summarize by saying that from the above and much 
other evidence in favor of both sides, it is quite probable that both 
secretion and filtration play important parts in the formation 
of body lymph. 

Lymph Vessels. — The formation of the various lymph 
vessels and their courses belongs to the subjects of histology and 
anatomy, and the student is urged to consult texts on these sub- 
jects. The lymph vessels differ in many ways from blood vessels. 
Their walls are thinner, they have valves opening in the direction 
of the veins toward which the lymph vessel is directed, and they are 



GENERAL AND OSTEOPATHIC. 41 

at various points collected into clusters or nodes, where they form 
glands. Certain constituents of the lymph, such as the lympho- 
cytes, are probably produced in these glands. There are two large 
lymph trunks, which empty their contents directly into the venous 
system. The thoracic duct, which extends from the receptacu- 
lum chyli or cistern of the chyle to the neck region, empties the 
chyle which has been collected by the lacteals from the villi of the 
intestine into the left subclavian at the junction of the internal 
jugular vein. The right lymphatic duct drains the right side of 
the chest, head and neck into the large veins of the right side. 
All lymph vessels ultimately empty into one of the large lymph 
channels or into the venous system directly. The serum of the 
blood, which escapes through the capillary walls, is taken up by 
the smaller lymph vessels, and after a time is carried back to the 
blood stream. 

Lymph Flow, Causes of. — Since there is no heart for main- 
tenance of the flow in the lymph vessels, other factors are responsi- 
ble for this function : 1. The increased pressure in the tissue spaces 
causes the lymph to flow into and through the small lymph vessels ; 
2. The contraction of muscles squeezes the lymph from the smaller 
vessels; and 3. The presence of valves in the lymph vessels which 
prevent the back flow of lymph causes its flow towards the large 
veins; 4. The variation in pressure in the thoracic cavity caused 
by respiratory movements — the so-called suction action — also 
assists in the flow of lymph. 

Functions of Lymph. — Since the blood does not come in 
direct contact with living body tissue cells anywhere, but is held 
separate from them by capillary walls, there is in most body struc- 
tures another medium of cell supply needed. In a few tissues, 
such as the lungs and liver, the tissue cells lie in immediate contact 
with the single-layered walls of the capillaries, and thus these 
cells may be directly supplied with nutrition from the blood and re- 
lieved of their wastes in a similar way. Many tissues are very 
avascular, and the cells of such tissues must receive their supply 
from tissue fluid or lymph, which is that portion of the blood which 
has escaped into the tissue spaces from the blood stream. 



42 PHYSIOLOGY I 

Cerebrospinal Fluid.— This is normally a clear, colorless 
fluid rich in sodium chlorid; contains small quantities of albumin, 
but contains no morphological blood elements; no fibrinogen and 
does not clot, which characteristics distinguish it from other lymph 
and blood. It is secreted principally by the cuboidal cells of the 
choroid plexus, a fold of pia mater which projects into the lateral 
ventricles. It has been shown that injection of extracts of choroid 
material increases the formation of cerebrospinal fluid. It has 
a specific gravity of about 1.006, and is constantly being secreted 
at the rate of about six drops per minute. 

This fluid may be found circulating between the arachnoid 
and pia mater, and continuing down the spinal cord. From the 
lateral ventricles, where it is produced, it passes to the third ven- 
tricle through the foramen of Monroe, and from here to the fourth 
ventricle by way of the aqueduct of Sylvius, and from the fourth 
ventricle it passes through the foramina of Magendie, Retzius 
and Key to the subarachnoid space; from the subarachnoid space 
a part of the fluid escapes into the sinuses of the dura mater by 
way of villous projections known as the Paccionian bodies. It 
also escapes by way ot the projections of the arachnoid, which 
extends outward around the cranial and spinal nerves. These 
projections are continuous with the lymphatics, and seem to 
have some function in supplying the nerve trunks with lymph. 

The functions of cerebrospinal fluid may be considered under 
separate headings, as follows : First, protection to the brain, spinal 
cord and nerve trunks from traumatic injury; second, this fluid 
forms an adjustable cushion for the brain and cord, which regu- 
lates the pressure about these structures by secretion and by 
drainage in such a way that the optimum pressure is properly 
regulated. Since the brain cannot withstand compression and 
since it is contained in a resisting case of firm bone, the 
increase in brain volume from congestion or from increased 
systemic blood pressure must be compensated for in some way, 
and the adjustable cushion of cerebrospinal fluid does this. These 
principles may be better understood when it is known that the 
withdrawal of a large quantity of cerebrospinal fluid, or an in- 



GENERAL AND OSTEOPATHIC. 43 

flammation preventing the normal escape of fluid from the brain 
or cord, which in either case would markedly vary the cranial 
pressure, is always followed by cerebral symptoms. Since the 
secretions of the posterior Jobe of the pituitary body are emptied 
chiefly into the cerebrospinal fluid, and since it is highly probable 
that this secretion is both detoxicatory and has some influence upon 
the spinal autonomic nerves, it may be that the presence of normal 
quantities of cerebrospinal fluid increases the resistance of the cord 
to infections, and the normal flow about the nerve trunks regulates 
the functional activities of the nerves. 

Osteopathic Considerations. — From the above physio- 
logical facts it would seem that lesions, subluxations, or rigidities 
of spinal segments would materially interfere with the drainage 
of cerebrospinal fluid from the cord. Lesions of the atlas or axis 
might prevent the drainage from the cranium, and either of these 
conditions would result in a failure of the regulation of the pres- 
sure in and about the brain and cord. This would certainly be 
followed by a variation of the functional activities of these struc- 
tures. Dr. A. T. Still holds that the function of certain visceral 
structures depending upon the nerve supply of the spinal autonom- 
ics (such as the gut in case of typhoid fever, etc.) are largely in- 
fluenced by the flow of cerebrospinal fluid, and this seems reason- 
able when we consider that this fluid is normally drained out by 
way of the nerve trunks, and that it does seem to give increased 
nerve tone to the sympathetics. Every osteopathic physician 
who has had much experience in treating acute infectious fevers 
knows that a thorough treatment of the spine is practically always 
followed by rest and sleep. That such treatment normalizes or 
tends to normalize the pressure to the cord and brain and thus 
lessen the cerebral symptoms is firmly established clinically. 

It may be that the detoxicatory and antibody-forming prop- 
erties of the cerebrospinal fluid is due in part to the secretions of 
the pituitary body. If so, any failure of the normal drainage of 
the fluids into or from the meninges of the cord would reduce this 
resisting mechanism, and spinal lesions would surely reduce the 
drainage. 



CHAPTER IV. 

ORGANS OF CIRCULATION. 

The Heart. — A study of the ontogenetic and phylogenetic 
development of any structure greatly aids in the understanding of 
its normal functions, and a thorough working knowledge of 
Haeckel's biogenic law will be found of great value to the student 
who wishes to know "the why of things physiological ". 

The study of the evolutionary descent of the mammalian 
heart is, in my opinion, of greater value in the understanding of its 
physiology than all other facts and theories gained from research. 

The primitive function of circulatory organs was not that of 
maintaining a blood flow, for there was and is no blood in the 
lowly forms of life, and just as " ontogeny repeats phytogeny" 
there is no blood in the higher forms of living animals at the time 
the heart begins to beat in the embryo. The function of that 
little mass of contracting cells arranged about a common body 
tube in the lowly forms of life was that of imperfectly circulating 
or keeping the body fluids in motion, that all tissue cells might re- 
ceive a fluid medium from which to collect nutrition and into which 
the wastes might be excreted. The primitive excretory appara- 
tus, the pronephros, was closely associated functionally with this 
simple circulatory mechanism that the wastes from the cells might 
be carried away. There were no valves in the primitive tube-heart, 
but the direction was given to the circulation by the wave of con- 
traction beginning at the end of this mass of contractile cells 
and moving continuously towards the other end, very much as a 
wave of peristalsis moves through a segment of gut, thus causing 
the body fluid to move in one direction. 

In the primitive body fluids there are no differentiated mor- 
phological structures such as corpuscles, which develop for the per- 

44 



GENERAL AND OSTEOPATHIC. 45 

formance of special functions, and this body fluid cannot, therefore, 
any more be properly called blood than can the simple contracting 
tube which causes its flow be called a heart. It is by a process 
of slow development and gradual differentiation of the various 
parts that these simple structures attain the form of the highly 
complex structure, the mammalian heart. 

These few hints are given here on the origin of the heart and 
circulation, that the reader may be better able to understand cer- 
tain explanations that are to follow. 

The Mammalian Heart. — In the mammalian or four- 
chambered heart it is well to consider the structure as a double 
mechanism, or two distinct hearts, since the right and left sides of 
the heart are functionally concerned with different parts of the 
circulatory process. By reference to the cut on page 47 this may be 
clearly seen. Each side of the heart consists of an auricle or upper 
chamber, which empties its contents through the valve into the 
ventricle below. The walls of the auricles are very thin, and their 
capacity is markedly small in comparison to that of the ventricles. 
The reason for this is the difference in the demand of function of 
the two structures. The blood, for example, is received into the 
auricles from veins in which the pressure is very little or nothing, 
and there is therefore no need of valves guarding the openings of 
these veins into the auricles. Furthermore, the only work of the 
auricle is that of completion of the filling of the ventricles, and the 
resisting pressure in the auricles is from 14 to 20 millimeters of 
mercury. The strong auriculo-ventricular valves, preventing the 
blood from flowing back into the auricles when the ventricles con- 
tract, protects the thin-walled auricles and their entering veins 
from the effects of back pressure. The ventricles, because they 
must force their contents against a much greater resisting pres- 
sure, must necessarily be stronger and their walls are therefore 
very much thicker than those of the auricles. The walls of the 
left ventricle are about four times thicker than those of the right 
ventricle. This is because the left ventricle must force the blood 
against the resistance offered by the entire systemic circulation 
— the greater circulation, while the blood from the right ventricle 
is forced only through the lungs— the lesser circulation. 



46 PHYSIOLOGY : 

Because the blood discharged from the right ventricle, after 
having passed through the lungs, must again pass through the 
left heart, the two ventricles must have the same capacity. The 
capacity of each ventricle is from 130 to 150 cubic centimeters 
when the heart is relaxed. During contraction of the ventricles 
about half of this quantity is expelled into the arteries. A fibro- 
tendinous ring separates the auricle from the ventricle, and from 
this ring most of the muscle fibres constituting the walls of the 
heart arise. The musculature of the heart is arranged in two lay- 
ers, circular and longitudinal. The circular fibres are continuous 
around both auricles and increased in thickness about the open- 
ings of the veins. The musculature of the heart should be care- 
fully studied from a text on anatomy, in order that the functions 
of the different layers may be understood. 

Valves of the Heart. — The direction of the blood flow through 
the heart is determined partly by the direction of the contrac- 
tion wave, but principally by the valves, which prevent the back 
flow. These valves are four in number, and guard the openings 
between the auricles and ventricles and prevent the back flow 
of the blood from the large arteries into the ventricles. The 
auriculo-ventricular valves consist of tubular membranes which are 
continuous with the endocardium, or inner layer of the heart, and 
are attached at their base to the auriculo-ventricular ring. The 
valve flaps consist of a base or central part, composed of fibrous 
and elastic tissue covered on both sides by endocardium. These 
valves project downward into the ventricles. The valve flaps 
are held in position and kept from being forced back into the auri- 
cles by many small tendinous cords (chorda tendinse) which 
arise from small projecting parts of the wall of the ventricle, the 
papillary muscles. During contraction (systole) of the ventricle 
these cords are drawn down, which action draws the valves more 
tightly together and prevents their being forced upward by the 
pressure of the blood in the cavity of the ventricle. The action 
of the valve is further aided by the contraction of the muscles 
of the fibro-tendinous ring at the base of the heart. This action 
reduces the size of this orifice during systole. The valve between 



GENERAL AND OSTEOPATHIC. 



47 



rt coronary. 

artery 

rfc coronary 

vein 




left coronary rein, 
left- coronary artery 



Ki Fig. 1. — This diagrammatic figure illustrates the blood flow through the heart and the 
blood supply to the heart musculature by way of the coronary circulation. Beginning at the 
left side of the figure above, the blood is shown to enter the right auricle of the heart from the 
vena cava. The second arrow shows the entrance of the coronary vein, which drains the 
blood from the musculature of the heart which has been supplied by the coronary arteries. 
From the right auricle the blood passes through the tricuspid valve into the right ventricle, as 
shown by the arrow, and from here it passes through the pulmonary semilunar valve into the 
pulmonary artery, which carries it to the lungs for oxygenation. The blood returns from the 
lungs by way of the pulmonary veins, which is diagrammatically shown in the figure. From 
the pulmonary veins the blood enters the right auricle of the heart, and from here it passes 
through the mitral or bicuspid valve into the left ventricle. The blood leaves the left ventricle 
through the aortic semilunar valve and enters the aorta. The coronary arteries are shown as 
being given on from the aorta, which is correct, these arteries being the first branches of the 
aorta, but instead of leaving the aorta at the point shown their openings really lie under the 
folds of the semilunar valves. Because of this arrangement the pulmonary valves fold back 
over these openings during ventricular systole and the openings to the coronary arteries are 
closed until the back pressure of the blood in the artery closes the valves. When this occurs 
the blood in the aorta tills the coronary arteries and the supply to the heart is effected during 
diastole of the heart, the significance of which has been explained elsewhere. 






48 PHYSIOLOGY : 

the right auricle and the right ventricle — the tricuspid — has 
three flaps, while the valve between the left auricle and the left 
ventricle — the bicuspid or mitral — has only two flaps. The 
student who experiences difficulty in remembering this may be 
helped by the key, " Martin Luther, the reformer — mitral left, 
tricuspid right." 

The valves guarding the large arteries — the semilunar — con- 
sist of three flaps or cups, which prevent the blood flowing back 
into' the ventricles after systole or contraction of the ventricles. 
These valves are comparatively much stronger than the auriculo- 
ventricular valves, and are therefore less often involved in diseased 
conditions of the heart. These valves are closed at all times when 
the blood pressure in the arteries is greater than in the ventricles. 
They are only open during the period of ventricular contraction 
and are held tightly closed by the pressure in the arteries forcing 
their free edges together during diastole. 

There are no valves at the openings of the large veins into the 
auricles. The contraction of the muscular rings at the openings 
of these veins performs the functions of valves, in that this action 
prevents any back flow of blood into the veins. 

The Pericardium. — The heart is suspended in a tough 
fibrous membrane, the pericardium, which is attached below to the 
central tendon of the diaphragm and attached above to the trunks 
of the large arteries. The pericardium has an inner lining of endo- 
thelium which is continuous with the outer covering of the heart. 
Between these two layers the pericardial fluid— a form of extra- 
vascular lymph — is found, which lubricates the walls, thus pre- 
venting friction and furnishing a water cushion for the protection 
of the heart. 

Blood Pressure in the Heart. — Many different methods 
have been devised for measuring the endocardiac pressure, but all 
have certain sources of error. The measurement of such blood 
pressures is very difficult, because of the quick rise and fall of 
the pressure caused by the contractions and relaxations of the 
heart muscle. The pressure in the left ventricle is the greatest of 
all of the chambers of the heart, because it is this part that has to 



GENEKAL AND OSTEOPATHIC. 49 

force the blood into the entire system of arteries and capillaries. 
The blood pressure in the left ventricle of a dog has been found 
to be from 130 to 200 millimeters of mercury during systole, and 
it is probably much higher than this in the human heart. The 
pressure in the ventricle must be great enough to overcome the 
resistance in the artery and to force the contained blood into it. 

The pressure in the right ventricle is much less than that in 
the left ventricle. The pressure in the pulmonary artery is about 
one-seventh or one-eighth that of the pressure in the aorta, and 
considering the pressure in the aorta to be 150 millimeters of mer- 
cury, the pressure in the pulmonary arteiy would not be more than 
25 millimeters of mercury; the pressure of the right ventricle 
would therefore be from 40 to 60 millimeters of mercury. 

The pressure in the auricles is much less than in either of the 
ventricles, since they have only to force the blood into the ventri- 
cles to complete their distension after they have been partly filled. 
The pressure in the auricles varies from 10 to 20 millimeters of 
mercury. 

The Cardiac Cycle. — The cardiac cycle consists of the 
various events of one heart beat which occur between two points 
of the same phase, and may be given as follows : The beat of the 
heart begins with a simultaneous systole of the auricles — about 
one-tenth of a second — which is followed by a pause of about one- 
tenth of a second. The contraction of the auricles is followed 
by the systole of the ventricles — about three-tenths of a second — 
the blood being forced into the large arteries. The period of 
diastole or rest lasts about four-tenths of a second. The effects 
and changes occurring during such a cycle are as follows: The 
auriculo-ventricular valves are closed only during the period of con- 
traction of the ventricles, while the semi-lunar valves are closed all 
the time except during contraction of the ventricles, when they are 
open to allow the passage of the blood into the large arteries. 
During ventricular systole the blood is forced from the right ven- 
tricle into the pulmonary artery and into the capillaries of the 
lungs. The increased pressure in the capillaries of the lungs be- 
cause of this maintains an almost even pressure back to the left 



50 physiology: 

auricle through the pulmonary veins. During systole of the left 
ventricle the blood in the arteries of the system is forced onward to 
the systemic capillaries and finally back to the right auricle by 
way of the venous system. 

The elastic retraction of the lungs causing a negative pressure 
in the thoracic cavity assists the flow of the blood from the large 
veins into the auricles. This so-called suction-pump action mate- 
rially assists in the " drawing" of the blood and lymph towards 
and into the thoracic vessels of the thoracic cavity, thus assisting 
the heart, and during the resting period of the heart the blood is 
continually flowing into and filling the auricles. Since the auriculo- 
ventricular valves offer little or no resistance, the blood from 
the auricles flows on through into the ventricles, partially filling 
them. During the contraction of the auricles the blood is forced 
into the ventricles, distending them. The auriculo-ventricular 
valves now float into position, and as the ventricles begin to con- 
tract these valves are forced tightly together, preventing the back 
flow into the auricles. The contraction of the ventricles begins 
very suddenly, and the outflow of the blood from them begins 
soon after the beginning of the ventricular systole. During dias- 
tole "the pressure in the ventricle cavity is quite small (only 
2 or 3 millimeters of Hg,) there is a pressure in the aorta of 50 to 
80 millimeters of Hg. " (Starling.) The pressure in the ventricles 
must be raised above this pressure in the arteries before the semi- 
lunar valves can be forced open. As soon as the ventricles have 
ceased contraction the pressure in the arteries closes the semi- 
lunar valves. 

Causes of Heart Beat. — Two theories, the neurogenic and 
myogenic, are advanced for the explanation of the causes of heart 
beat, which will be briefly discussed. 

Supporters of the neurogenic theory offer the following evi- 
dence of its value : The existence of an automatic motor center 
at the junction of the auricles and large veins, which seems to be 
responsible for the initiation of the contraction wave. Adherents 
of this theory assume that the excitation of the stimulus arises 
within this nerve mechanism, and that these nerve cells constitute 



GENERAL AND OSTEOPATHIC. 51 

the automatic motor center of stimulation for heart muscle. The 
contraction wave spreads from these points downward over the 
auricles and thence to the ventricles, and it is supposed that the 
impulses are transmitted by way of the axones extending from 
these nerve cells. These nerve centers with other secondary or 
subordinate centers constitute the intrinsic nerve mechanism of 
the heart, which, according to this theory, is responsible for the 
spontaneous origination and progression of the rhythmical activity 
of the heart. It is assumed that this equal stimulation of the 
musculature by the action of these nerve fibers is responsible for 
the normal co-ordinated movements of the heart, such as fibrillar 
contractions. Results of physiological research have in many 
ways borne out the above theory, but histologically there is in- 
sufficient confirmatory evidence. 

It is true that most of the phenomena of the heart beat and 
its regulation can be explained by this theory, but, as will be shown, 
the same is true of the myogenic theory. Again it seems that no 
positive facts have been offered against the theory. On the other 
hand, there is no positive evidence that the nerve supply of the 
heart is actually causative of its functional activity. The most 
suggestive argument in favor of the neurogenic theory is the fact 
that if a needle be thrust into the normally functioning mamma- 
lian heart (a certain part of the ventricle and known as the puncture 
of Kronecker) the regularity of the contraction of the ventricles 
is distuibed and fibrillar contractions result. This area is not a 
large one, and if the needle thrust does not pass through this 
specific " center" the regular co-ordinated beat of the heart is not 
affected. The structural nature of this "center" has never been 
determined, and since the puncture so often fails to produce the 
irregular contractions, there is no positive proof that it controls 
or initiates the stimulus causative of the heart beat. 

A series of experiments made by Carlson on the horseshoe 
crab shows quite conclusively that in this case, at least, the rhyth- 
mical contractions depend upon the intrinsic nerve plexuses, but 
whether these facts can be applied to the functions of the mamma- 
lian heart is questionable. 



52 PHYSIOLOGY : 

The Myogenic Theory. — By this theory it is assumed that 
the heart is possessed with the property of rhythmical contrac- 
tion, and that this inherent property of the protoplasm has been 
developed in answer to a demand of function until it fulfills the 
functional requirements. It is assumed that this power of rhyth- 
micity has been developed most highly at the portion of the heart 
where the large veins enter the auricles, and now by reference to 
the brief notes on the phylogenesis of the heart in the beginning of 
this chapter, a reason for this may be clearly seen. It may also 
be seen why the wave of contraction spreads from this point first 
to the auricles and then to the ventricles as one progressive move- 
ment. It must be remembered that in the heart, as well as in 
the intestine, the musucular movement is that of a peristalsis — 
consisting of a gradually progressive wave of dilation followed by 
constriction. In the igtestine and in the primitive heart this may 
be readily demonstrated, but in the more highly developed hearts 
the special structural anangement is such that the wave becomes 
segmented rather than regularly progressive. 

The chief evidences of the myogenic theory will be briefly 
given : » 

1. A study of the anatomical arrangement of the various 
muscular layers of the heart will show that it is structurally 
adapted to the action of a progressive wave of contraction. The 
auriculo-ventricular bundle, connecting the musculature of the 
auricles with that of the ventricles, makes the continuation of a 
muscular wave possible. 

2. The nerve mechanism connecting the auricles and ven- 
tricles may be removed without disturbing the normal rhythmical 
contraction of the heart, thus tending to disprove the neurogenic 
theory. 

3. Anything that directly affects the auriculo-ventricular 
bundle, thus preventing the regular progression of the wave, 
disturbs the rhythmical contraction of the heart. It has been 
shown by Stannius that if ligatures be placed about the heart at 
various places the rhythmical contractions are disturbed. In 
various other ways, such as by section or otherwise, if the normal 



GENERAL AND OSTEOPATHIC. 53 

connection of this auriculo-ventricular band is disturbed the 
heart rhythm is interfered with. Adherents to the myogenic theory 
have endeavored to explain this by arguing that this band contains 
nerve fibres which are effective in the transmission of impulses. 

4. It has been shown by Englemann that a heart may be 
sectioned in various ways, which sections would surely cut all 
nerve connections, but if small portions of intervening muscle 
remained between a contraction wave would progress from above 
downward, passing over these muscular bridges, which cannot be 
explained by the neurogenic theory. 

5. The theoretical reasons as given above for believing in 
the autonomic rhythmical properties of heart muscle are sub- 
stantiated by the experimental work of Gaskell and others, which 
shows that muscles of poikilothermous animals, when cut into 
strips, are still possessed with the power of rhythmical contraction. 
It may be that these strips of muscle contain nerve cells or cells 
and fibres, but the results surely show a tendency to the so-called 
inherent property of rhythmical contraction which all heart muscle 
possesses. 

6. It may be shown that the heart of an embryo chick begins 
to beat within from twenty-four to thirty-six hours after incuba- 
tion is started. It may further be shown that there are no nerves 
associated in any way with the heart at this time, and so from these 
facts it is most positive that the musculature (mesodermic con- 
tractile cells which function as heart muscle) only can be re- 
sponsible for these movements. At this stage of development 
there could be no possible nesve connection with the heart, as the 
neural tube, the forerunner of the cord, is only in the process of 
development, and there are no projections from it which could 
possibly be associated with the heart, the two structures being 
developed entirely separate — the heart originating from meso- 
derm and the nerual tube coming from ectoderm. 

Summary of Causes of Heart Beat. — Since there is so 
much theory and so little information in the above, we may say 
that from the developmental argument and considering the rest as 
secondary, it seems logical to conclude that the first and probably 



54 PHYSIOLOGY I 

the continued chief cause of heart beat is that inherent property 
of the mesodermic cells which renders them highly contractile, 
and that this property is also, to some extent at least, responsible 
for the automaticity and rhythmical activity of heart muscle. 

Developmentally the nerve supply comes as a secondary struct- 
ure, and probably serves to associate the functional activities of 
the heart with the demands of other parts of the body. The chief 
functions of the cardiac nerves would seem to be that of associa- 
tion and adaptation of the heart functions to the demands of the 
body as a whole. Physiologists as a rule, we believe, are too apt 
to place too great functional value on some particular structure, 
forgetting that it is only a part of the entire body machine. It is 
highly essential that the functions of the heart must depend for 
their regulation upon some mechanism which will associate these 
functions and regulate them to the demands of the body as a 
whole, and this seems to be the chief purpose of the cardiac nerves. 

Tone of Heart Muscle. — Another function of the nerves 
to heart muscle is that of giving tone to the muscle fibres. As 
will be shown in the chapter on muscle physiology, the power of 
muscle fibres to contract, depends largely upon the low degree of 
stimulus which is constantly being sent to the muscle fibres by way 
of the nerves which supply them. So long as the nerve supply is 
normally active the muscle fibres exist in a state of partial con- 
traction, which makes them ready to receive and respond to a 
stronger stimulus. This property of muscle tone of cardiac 
muscle is therefore due to the nerve supply. 



CHAPTER V. 

NERVE SUPPLY TO THE HEART. 

As has been given, the chief cause of the heart beat is some 
inherent power of the muscles of the heart to contractrhy thmically, 
but it cannot be denied that certain nerves have a very important 
function to perform in the regulation of the force and rate of the 
heart beat. The circulation of blood is also controlled by those 
nerve fibres which supply the blood vessels and regulate the 
quantity of blood suppled to various structures, by causing varia- 
tions in the size of the lumina of the supplying arteries. 

The Cardiac Nerves. — The heart is supplied by two sets 
of efferent nerve fibers which arise primarily from the centra] 
nervous system. These sets of fibers arise from different parts of 
the central system. Their origin and development are different, 
and, as may be expected, the functions in the regulation of the 
action of the heart are also different. They act antagonistically, and 
in this way perform a regulatory function when acting together. 

The Vagi. — The pneumogastrics or tenth cranial nerves, 
commonly known as the vagi, supply the heart with fibres which 
are inhibitory in function, and are therefore generally known as 
the cardio-inhibitors as opposed to the other nerve supply, which 
is accelerator in action. 

The Branches of the Vagus. — Superior cardiac, which 
supply the heart, are given off from the vagus above the superior 
laryngeal, and the inferior cardiac branches are given off from the 
thoracic part of the nerve. It is thought that the inhibitory 
fibers arise chiefly from the inferior branches. These fibers, 
superior and inferior, unite with the branches of the spinal auto- 
nomic system (sympathetics) to form the common cardiac plexuses 
which lie on the arch of the aorta. The nerve fibers that supply 

55 . 



56 physiology: 

the heart directly extend from these plexuses and consist of both 
accelerator and inhibitor fibres. Some fibres may extend directly 
to or into the heart muscle, where they terminate about certain 
intrinsic ganglion cells and have other (post ganglionic) fibers 
distributed from this point to other parts of the heart. 

Evidence of Inhibitory Action of the Vagus. — This 
function of the pneumogastric nerves may be demonstrated di- 
rectly on animals by sectioning the vagus nerve of a living ani- 
mal while a blood pressure or heart tracing is being made on a 
kymograph. Upon section of one vagus the heart rate will mate- 
rially increase (there may be a few seconds of inhibition due to the 
stimulus to the nerve by handling and cutting), and will usually 
remain increased for some time. The explanation is that the 
vagus nerves normally send a certain amount of stimulus to the 
heart which tends to retard its function, and the cutting of one 
vagus stops one-half of this retarding influence. Since the spinal 
autonomics are functioning in exactly the opposite way, i. e., 
tending to increase or accelerate the heart beat, this regulatory 
influence is now acting out of proportion and the heart is receiving 
an excess of accelerator nerve stimulus in proportion to the 
inhibiting nerve stimulus. The rate is therefore increased. 

Further experimental evidence may be had by cutting the 
other vagus, when another marked increase will be noted, and the 
explanation is the same as given for the causes of the changes 
occurring from the cutting of the first nerve. 

If after the section of one or both vagi an artificial stimulus 
is applied to the peripheral end (the end leading toward the heart) 
of the nerve or nerves, the rate is quickly reduced and held so, as 
long as the stimulation is maintained. The amount of cardiac 
depression resulting from vagal stimulation varies directly with 
the strength of the stimulus. That is, if a light stimulus is applied 
and the amount of cardiac depression recorded, the application 
of a stronger stimulus will be followed by a greater depression of 
the heart's function. 

If a very strong stimulus, such as an electrical stimulus from 
an induction coil be quickly applied, the heart may and usually 



GENERAL AND OSTEOPATHIC. 57 

does stop entirely, but recovery usually results. The amount of 
cardiac depression resulting from vagal stimulation varies with 
different species, and also with various individuals of the same 
species. This inhibitory influence of the vagus on the heart was 
first demonstrated by the Weber brothers in 1845, which was the 
beginning of the many discoveries of the functions of the cardiac 
nerves. 

Nature of Effects of the Inhibition. — When the peripheral 
end of the vagus is stimulated it may be shown that the heart 
beat is decreased in both rate and amplitude. The quantity of 
blood forced into the arteries is therefore decreased, and this, in 
addition to the slowing of the rate of heart beat, results in a de- 
crease in arterial blood pressure. 

The Inhibitory Center. — The nucleus ambiguus, the motor 
nucleus of the tenth nerve, contains certain cells to which the 
function of cardio-inhibition is attributed, and this group of cells 
is commonly considered to be the center for reflex or autonomic 
regulation of the inhibitory influence upon the heart caused by 
certain fibers of the vagus nerve. The exact part of the vagal 
center which contains these inhibitory cells has never been definitely 
located, but its existence has been demonstrated by the study 
of reflex effects. Like other centers, this center is bi-lateral — 
one on each side, each having to do with fibers for its own nerve. 
It is possible that these two centers are connected by commissural 
cells, as the stimulation of one center seems to influence both. 
If, for example, one vagus nerve be sectioned and a stimulus ap- 
plied to its central end (the end leading into the medulla) a de- 
crease in the rate of heart beat sometimes follows. When this 
occurs it is possible to explain such action by assuming that the 
stimulus passed into the center of the stimulated side crossed and 
passed down by way of the other vagus. This is the explanation 
generally offered, but the author, after having tested this on more 
that one hundred animals, found that when the central end of one 
cut vagus was stimulated, the result was almost invariably an in- 
crease instead of a decrease in heart rate and blood pressure. An 
explanation of this will be offered later. It seems more reasonable 



58 PHYSIOLOGY : 

to assume, as some authorities now do, that the centers of the vagi 
send out two groups of fibers — one group, the larger one, passing 
to the vagal trunk of the same side and a few passing to the vagal 
trunk of the opposite side. These crossing fibres are comparatively 
few in numbers compared with the direct fibers, but this could 
easily explain how, in the few instances, the stimulation of one 
vagal center could influence the opposite nerve. 

Reflex Action of the Cardio-Inhibitors. — It was shown by 
Goltz that the inhibiting functions of the vagi could be influenced 
by stimulation of certain afferent or sensory nerve paths. He 
showed, for example, that tapping the abdomen of a frog would 
inhibit the heart and often completely stop its beating. This 
author further found that such results were not obtained in frogs 
in which the vagi had been sectioned. 

As mentioned above, it has been found that in some mammals 
the stimulation of the central end of one cut vagus will be followed 
by cardio-inhibition, although this does not seem to be the common 
rule. It is probable that the vagus contains afferent (ingoing) 
fibres from the abdominal and thoracic viscera, the stimulation of 
which may result in a reflex cardio-inhibition by exciting the 
cardio-inhibitory center to greater activity, which causes a greater 
number of efferent (outgoing) stimuli to be sent to the heart muscle 
by way of the cardio-inhibitory fibers. 

This is the explanation of how a sudden blow on the abdomi- 
nal wall, over-distension of the stomach from gas or a large meal, 
acute gastric pains, etc., may sometimes cause variation in heart 
action. 

Cause of Inhibition. — Many theories have arisen for the 
explanation of the way in which the inhibition is effected. It 
has been shown that the inhibitory influence of the vagus is not 
caused by any special properties of the fibres or the nature of the 
impulses, but is probably due to the particular part of the heart 
in which these fibres terminate. It has been shown by Erlanger 
that if another of the cranial nerves (fifth cranial) be sutured to 
the peripheral end of the cut vagus and sufficient time allowed for 
regeneration, a stimulus applied to this regenerated fifth nerve will 



** s *"*s^%» sv 




GENERAL AND OSTEOPATHIC. 59 

be followed by cardio-inhibition as in case of the vagus. Gaskell, 
who has done some interesting work on this subject, believes that 
the cause of inhibition lies in the kind of metabolic changes effected 
in the heart, which are opposite from those occurring during con- 
traction. He believes that during contraction the chemical 
changes are catabolic, resulting in the liberation of the stored-up 
(potential) energy, thus giving energy for muscle work (see muscle 
physiology), and that during inhibition the opposite metabolic 
reaction occurs, which is anabolic or synthetic in nature, resulting 
in giving to the heart a greater power of energy for contraction. 
It must be admitted that the theory seems logical and that this 
author has developed not a little experimental evidence in its 
favor. The principles of the theory will be better understood by 
a careful reading of the cause of muscle contraction and the 
sources of muscle energy. (See index.) 

Drugs and Cardio-inhibition. — Certain drugs when in- 
jected subcutaneously or intravenously produce changes in the 
rate and force of heart beat. Atropin causes a quickening of the 
heart similar to that caused by the cutting of the vagi, and since 
stimulation of the peripheral end of the vagus fails to produce 
inhibition after the administration of atropin, it is assumed that 
the atropin paralyzes the post-ganglionic fibres of the heart muscle 
(the endings) of the vagus. Curare produces similar effects on 
smooth muscle, the drug affecting the motor end plates, as will be 
given later. Just the opposite effect is obtained when muscarin or 
pilocarpin is used instead of atropin. If an injection is made of 
muscarin or pilocarpin the heart rate is decreased, and if the dose 
is sufficiently large or if the injections be continued, complete 
cessation of the heartbeat results. This effect can be relieved 
or prevented if the injection is followed by an injection of atropin. 
It is therefore assumed that muscarin and pilocarpin stimulate 
the post-ganglionic fibres of the vagus. Some authorities believe 
these drugs produce their effects by some specific action on the 
heart muscle. The reader may find additional information on 
this subject in texts on pharmacology. We can only say, regard- 



60 PHYSIOLOGY : 

ing the action of these drug?, that no positive information can be 
found on the subject. 

The Cardlo- Accelerators. — The nerve fibres supplying the 
heart from the spinal autonomics — the cardio-accelerators — are 
efferent or motor nerves originating from the so-called sympa- 
thetic system. There is some variation in the course of these 
fibres and their method of distribution, but for the most part 
their course and functions are about the same in all mammals. 

Origin and Distribution. — These fibres originate from cells 
which lie in the anterior horn of the gray matter of the spinal cord 
of the second, third and fourth segments of the thoracic area of 
the spinal cord. Their fibres pass out with the anterior roots of 
the spinal nerves of these segments. It is claimed by some author- 
ities that they may be found in the anterior spinal nerves from the 
first to the fifth thoracic segments, inclusive. These fibres (white 
rami) pass to the first thoracic (stellate) ganglion and from here 
byway of the annulus of Vieussens to the inferior cervical ganglion. 
See plates II and III. Some of the fibres pass from here to the 
cardiac plexus and from this plexus to the heart. These fibres 
constitute a part of the cardio-accelerators, which continue with 
some of the cardio-inhibitory fibres of the vagus to the plexus. 

The pre-ganglionic portion of the axon which extends from 
the cell in the cord may terminate in the stellate ganglion or the 
inferior cervical ganglion. These axones (processes extending 
from the cell body) terminate about another cell body, and this 
second cell with its axon which extends onward, constitutes the 
post-ganglionic fibre. 

Function of the Cardio-Accelerators. — As evidence of 
the accelerator function of these fibres, stimulatory experiments 
may be tried. If artificial stimulus be applied to the stellate 
ganglion, the inferior cervical ganglion or the peripheral ends 
of the sectioned nerves, a marked increase in the heart beat, both 
rate and amplitude, results. If these fibres are cut a marked 
slowing of the heart follows. The explanation is that the cutting 
prevents the supply of the normal amount of stimulus which 
tends to accelerate the heart, and the inhibitory influence of the 






GENERAL AND OSTEOPATHIC. 61 

fibres of the vagus cause the depression. This is further confirmed 
by the increase in the heart rate by stimulation of the peripheral 
ends of these fibres after the depression has resulted from the 
cutting. 

Whether these special fibres have other functions on the heart 
is not positively known.. It has been suggested that they may 
have trophic functions to the heart muscle, but it seems most 
probable that they only tend to liberate the energy stored up, 
and in this way cause the increased functional activity of heart 
muscle. 

Nature of the Acceleration. — Stimulation of these fibres 
or their cell ganglia produces a very marked increase in the heart 
beat. The rate is often increased from fifty to seventy per cent, 
and remains so for some time after the stimulus is removed. The 
blood pressure in the arteries is not always increased by such 
stimuli, as the rate may be increased while the amplitude of con- 
traction remains the same or is decreased, and there is therefore 
no more blood expelled from the heart than normally, but with the 
increased rate there is usually an increase in the quantity of blood 
thrown out at each contraction, and the blood pressure is there- 
fore nearly always increased in proportion to the rate of the heart 
beat. Some authors hold that there are two types of acceleration 
fibres: 1. Those that only increase the rate of the heart beat, 
the accelerators proper; and 2. Those that are concerned with 
the increase in the amplitude or force of the beat — the augmentors 
— which cause the heart to expel a greater amount of blood at 
each beat. It is further claimed by some that the course of these 
different fibres is known, and that the accelerators come fiom the 
right plexuses while the augmentors arise from the left plexuses. 

The Car dio- Accelerator Centers. — It is thought that 
there is a center in the medulla from which fibres are sent downward 
to the cell bodies lying in the upper dorsal segments of the spinal 
cord. The fact that stimulation of the upper cervical region of 
the cord produces acceleration of the heart is generally considered 
to be evidence of this. It has been conclusively shown (Deason 
and Robb) that stimulation of the central ends of nerves which 



62 



PHYSIOLOGY : 



arise from the medulla or cervical cord, 
such as the vagi or phrenics, also produces 
cardio-acceleration, and this might also 
be considered as evidence of the existence 
of such a center, but this effect can be 
obtained from the stimulation of the 
central end of almost any sensory or 
mixed nerve, and it would therefore seem 
that this evidence is not entirely con- 
clusive. If such a primary center does 
exist in the medulla there is surely another 
center or centers (they may be considered 
reflex transfer stations) in the upper 
dorsal, and possibly the lower cervical 
segments of the cord, which also take 
some part in the regulation of these 
functions. 

The upper tracing in this figure 
represents the respiration while the lower 
tracing represents the heart beat and 
blood pressure. The line beneath is the 
base line, the white areas of which repre- 
sent the time during which stimulation 
was being applied. It will be observed 
that the stimulation affected both respira- 
tion and blood pressure. The second 
normal represents the period of rest after 
the first stimulation, and it will be seen 
that while neither the blood pressure nor 
the respiration returned to normal there 
was a second very marked increase when 
the second stimulus was applied. 

Reflex and Tonic Activities. — The 
experimental evidence, the effects ob- 
tained from afferent stimulation, leads 
us to conclude that the activity of 
these centers is maintained and influenced 



Fig. 2. 



Plate IV — This chart shows the 
heart and its chief vessels with some of 
the spinal nerves: 1, Oblongata; 2, su- 
perior cervical ganglion; 3, vertebral 
artery; 4, middle cervical ganglion; 5, 
inferior cervical ganglion; 6, brachial 
plexus; 7, arch of aorta; 8, pulmonary 
arteries; 9, pulmonary veins ; 10, heart; 
11, inferior vena cava; X, aorta; 12, 
spinal cord; 13, abdominal aorta; 14, 
end of spinal cord; 15, lumbar nerves; 
16, iliac vessels; 17. cauda equina; 18, 
femoral vessels; 19. great sciatic nerve. 




GENERAL AND OSTEOPATHIC. 63 

largely by afferent (sensory) stimuli coming in from the periphery. 
It has many times been shown that the stimulation of sensory 
nerves leading into the cord causes a marked increase in the activity 
of these accelerator fibres. 

It may also be shown that the accelerator fibres are normally 
in a state of tonic activity, by cutting one or both of the groups 
of fibres leading to the heart. If these fibres are sectioned the 
heart rate is materially reduced by the activity of the vagi. This 
shows that a certain amount of stimulus is constantly passing to 
the heart by way of these fibres which is accelerator in action. 

The Functional Balance. — The value of such a physio- 
logical balance of function which is constantly maintained by the 
antagonistic action of the inhibitors and accelerators can readily 
be seen when it is understood that, in order to obtain necessary 
variations of functional activity of an organ by reflex effects, such 
a mechanism must exist. • When a structure is so regulated in its 
activities and a normal amount of tone of the structure exists 
from the effects of both of these nerve supplies, it is only necessary 
that one of them have its action increased or the other inhibited 
to cause the change needed to adapt the animal to sudden demand 
of function. 

This is, therefore, a mechanism by means of which the animal 
may reflexly adapt itself to certain immediate environmental de- 
mands of function. Under certain conditions, such as in the case 
of animals in combat for example, there is a demand for an increased 
blood pressure, etc., which is effected reflexly by stimulation of 
the centers or cell bodies of the accelerators in the central nervous 
system. 

It is also known that the mental state of the individual often 
influences this heart-regulating mechanism. Certain emotions 
are known to cause heart variations, which may be explained by 
assuming the existence of a connection of these heart-regulating 
centers with certain brain centers. 



CHAPTER VI. 
NERVE SUPPLY TO THE BLOOD VESSELS. 

The Vasomotor Nerves. — Claud Bernard in 1857 found that 
the spinal autonomic fibers distributed from the lateral chain 
contained fibers which regulated the size of the blood vessels by 
causing variations in the size of their lumina, and in this way 
varying the quantity and pressure of blood. The elastic property 
of the arteries had been thought to determine the adaptability 
of the blood-supplying vessels up to this time. 

Evidence of Vasomotor Fibers. — It may be shown 
by sectioning the spinal autonomics (sympathetics) in the neck 
of the rabbit, that the vessels of the ear of the same side become 
much dilated. This was Bernard's classical experiment which 
first demonstrated the presence of such fibers. It may be further 
shown that if the peripheral end of this cut nerve be stimulated, 
the vessels of the ear constrict and the ear becomes blanched 
from the lack of blood. This may be shown in both ears at the 
same time by stimulating simultaneously the peripheral ends of 
the autonomics on both sides, or if one side be cut and the other 
stimulated, the ear on the cut side will become reddened while 
the other will be blanched at the same time. 

Kinds of Vasomotors. — It has been found that the stimu- 
latiou of certain nerve trunks or fibers, or in some instances the 
ganglia or segments of the spinal cord, causes a constriction of 
the small arteries supplying certain structures. Because of this 
effect, these fibers are termed vaso-constrictors. It has also been 
found (first by Bernard) that the stimulation of certain other 
nerves causes just the opposite effect or dilation of the vessels, 
and these fibers are therefore known as the vaso-dilators. 

These two sets of fibers therefore regulate the size of the small 
arteries in such a way as to determine the supply of blood to 
64 




Plate I. — The Circulation of the Blood. 1. Left common carotid; 2. left pneumo- 
gastric nerve; 3. internal jugular vein; 4. left subclavian artery; 5. trachea; 6. right recur- 
rent laryngeal nerve; 7. innominate artery; 8. left recurrent laryngeal nerve; 9. pulmonary 
vein; 10. pulmonary artery; 11. mouth of left coronary artery; 12. semilunar valve; 13. 
coronary vessels; 14. inferior vena cava; 15. hepatic veins; 16. aorta; 17. hepatic arterv; 18. 
gastric artery; 19. cceliac plexus; 20. portal vein; 21. splanchnic artery; 22. superior mesen- 
teric artery; 23. renal artery; 24. inferior mesenteric vein; 25. superior mesenteric vein; 26. 
inferior vena cava; 27. common iliac artery. 






> A 



Czz 



O' 



GENERAL AND OSTEOPATHIC. 



65 



certain structures. The salivary glands furnish a good example 
of such a regulation of function. The spinal autonomi c fibers which 
are supplied to these glands by way of their arteries are vaso- 
constrictors, and stimulation of these fibers causes a decreased 
supply of blood to the glands and a temporary increase in the 
blood pressure of the vessels of the glands. Other fibres which 
are distributed to the glands by way of certain cranial nerves are 
vaso-dilators, and it may be shown that the stimulation of these 

fibers causes a dilation of the blood 
vessels of the glands and a decrease of 
the pressure within the vessels. The 
physiological value of such a mechanism 
will be found given in the discussion of 
the function of these glands. 

Methods of Study of Vasomotor 
Effects. — As explained above under 
" Evidence of Vasomotor Fibers/' the 
existence of such nerve fibers and their 
functions may be studied: 

1 . By observing the structure while 
its nerve supply is being stimulated. 
If the structure receives vasomotor 
fibers, it may be seen to blanch while 
the nerves are being stimulated, and 
after the stimulus is removed it may 
be seen to become congested. 
2. Various instruments have been devised for determining 
the blood supply to a part, some of which are of value. The 
plethysmograph, one of the most commonly used, consists of a 
tube into which the finger or arm may be placed. The space 
about the arm is fitted tightly with a wide rubber band in such a 
way as to make the space about the arm water-tight. A small 
tube leads from the space about the arm to some kind of recording 
apparatus. The space about the arm is filled with water at about 
body temperature, and the arm is held firmly to prevent move- 
ment. By the application of cold or hot packs on the arm out- 




Fig. 3. — Hand-form plethys- 
mograph. A, base; b, hand grip; 
c, hand; d, diaphragm; e, tube to 
recording apparatus. 



66 



PHYSIOLOGY : 



side of the plethysmograph it may be shown that variations in 
the volume of the water contained about the arm in the plethys- 
mograph can be effected. Any increase means vaso-dilation of 
the vessels of the arm, which causes an increase in the volume of 
the arm. Any decrease of the volume of water within the plethys- 
mograph means vaso-constriction. Plethysmographs have been 
devised for the study of blood-pressure changes in various glands, 
such as the kidney, spleen, etc. They are made to fit the structure 
as closely as possible, and have a rubber sack which is held in a 
metallic case. The sack contains some kind of fluid that the 
structure may displace during expansion. 

3. Vasomotor effects may also be determined by measuring 
the quantity of blood thrown off by the veins. If this quantity 
is increased by stimulation of the nerve supply to the structure 
it is known that vaso-dilation has resulted from the stimulation. 
If the quantity of blood is decreased, it is known that the opposite 
effect or vaso-constriction has occurred. 

Vasomotor Centers. — It has been shown that if the spinal 
cord be cut in the cervical or upper dorsal region, the vaso- 
constrictor fibers lose their tone or power to maintain the normal 
amount of tension of the smooth muscles of the arteries which 
they supply, and vaso-dilation is the result. It is therefore 
supposed that there is some center or centers in the brain, probably 
in the medulla, which influence this vaso-constriction function. 
It is supposed that fiber paths (axones) from the cells in these 
"higher centers " extend downward in the spinal cord and termi- 




Fig. 4. — This tracing shows the result of electrical stimulation applied to the central end 
of the sciatic nerve in the normal animal. It will be noted that a marked increase in the blood 
pressure resulted from the stimulation. If, after such tests have been made, a lesion be placed 
in the mid-dorsal region of the animal and the stimulation repeated, no increase of blood pres- 
sure results, which fact shows that the lesion has in some way interferred with the norma! func- 
tions of the reflex mechanism causing abnormal results from the stimulation. 



GENERAL AND OSTEOPATHIC. 67 

nate about other cells or groups of cells at various (probably all) 
levels of the cord, which groups of cells may be considered as the 
secondary or cord centers. The cells of the cord lie in the antero- 
lateral portion of the gray matter, and send their axones out 
with the anterior spinal nerve root. This axon is the pre- 
ganglionic portion which terminates in some other ganglion, from 
which a post-ganglionic fibre continues to the structure supplied. 
It is generally considered that there is a similar center for the 
regulation of vaso-dilation effects, since these functions are con- 
trolled in a similar way to the vaso-constrictors. It is further 
supposed by some that a primary center for the regulation of 
this function is located somewhere in the brain, but the positive 
evidence is lacking. It has been established that there are 
"centers" in the cord, i. e., certain areas, the stimulation of 
which will cause vaso-dilation in certain structures. This subject 
of the " Spinal Cord Centers" will be discussed elsewhere. 

Vasomotor Reflexes. — Since it has been shown that certain 
more or less definite areas exist which may be called centers, from 
which axones extend which control these funtcions, it may be 
assumed with good reason that these so-called centers may be 
and are influenced by sensory or afferent impulses, and in this 
way their functions may be affected. A certain amount of normal 
afferent or incoming stimulus probably keeps these cells active, 




Fig. 5. — This tracing shows the results of stimulation of the central end of the sciatic 
nerve on respiration and blood pressure. The upper line represents the respiratory tracing 
and the lower line represents the blood-pressure effects. The time rate is represented between 
the two drawings. The white parts in the base line show the time and length of the stimula- 
tion. It will be noted that a marked increase in respiration and blood pressure due to an in- 
creased functional activity of the centers results from the stimulation of the central end of 
spinal nerves. The normal stimulation, which comes in from the sensory surfaces by way of 
these nerves, is responsible for the maintenance of normal tone of these centers, thus regulating 
the functions of the structures supplied by the efferent autonomic nerves. 



68 <»■•■!< -physiology: . 

and in this way normal tone of the vaso-motors is effected, which 
keeps the smooth muscle supplied by them in a state of constant 
partial contraction. 

There is also good experimental evidence to show that these 
afferent fibres are of different kinds. Those the stimulation of 
which causes an increased activity of the vaso-constrictor centers 
and therefore a vaso-constriction, are known as the " pressor 
fibers/' and those which diminish the tone of the vaso-constrictor 
centers and by this means cause a vaso-dilation, are known as the 
"depressor fibers." These effects are, of course, all effected 
reflexly. It seems reasonable to assume that the blood pressure 
in different structures and in the entire system may be regulated 
by such a mechanism, and that these fibers— the afferent and 
efferent mechanism- — form an important physiological associa- 
tion of internal functions to external environmental changes. 




Fig. 6. — This figure shows the result of the stimulation of the central end of a spinal or 
cranial nerve. The reflex effect on the center results in an increased activity of these centers, 
which is followed by an increase in respiration, an increase in blood pressure due to reflex vaso- 
constriction, and there is usually an increase in the rate of the heart beat. The upper line in 
this figure shows the increase in respiration and the lower line shows the increase in blood pres- 
sure. 

Course and Distribution of the Vasomotors. — Since the 
origin, course, and distribution of the vaso-dilator fibers is dif- 
ferent from that of the constrictors, it becomes necessary to discuss 
them separately. 

The Vaso- Constrictors. — The fibres constituting this 
system all belong to the spinal autonomics. The cell bodies 
which give rise to these fibers lie in the antero-lateral part of the 



OPTH.DlV. 
CILIARY CAflGUOtl 



SUP MAX.DiV. 
INTERVAL CAROTID ART. 
Hi F MAX. DiV. 



VERTEBRAL VESSEL 
SUP. CERV. CAN 6. 

3d CERV GANG. ROTATED 



EXT. CAROTID ARTERY 
LINGUAL ARTERY 



INT. JUG. VEIN. 

TilD.CER.6ANC. 

LARYNX 

RT COM. CAROTID ARTERY 

PNEUMOGASTRIC NERVE 
INF. CER. GANG- 




ht THOR. GANG. 
THYROID CLAUD 
R. SUBCLAVIAN ART. 
Z<l THOR. VERJEBRA ROTATED 

RT. 1NH0M ART 



L./NNOM. ART. 
-PULM PLEXUS 

AORTA 

DEEP CARD. PLEX. 
■SUPERP CARD. PLEX 
GANG. OF Wlfl5BEIf6 

PULM. ART. 



COR. PEEK. 

R. COR. PLEX. 

7th THOR VERT ROTATED 



ESOPHAGEAL PLEX. 
DIAPHRAGM 



Plate VI. — The various nerves forming plexuses and controlling the functions of the 
bronchia! tubes are shown in this cut, also their communication with the cerebro-spinal nerves 
through the rami. The anterior and posterior pulmonarv plexuses are shown in front of and 
back of the bronchial tubes. These are formed almost entirelv from the svmpathetic and 
pneumogastric nerves (the pneumo branch of the pneumogas'tric) . The spinal nerves are 
shown, also the small fibers connecting them with the sympathetic chain. The second thoracic 
vertebra is shown rotated, in dotted lines. Notice the close connection between the nerves 
leading to the bronchial tubes and the cardiac, leading to the heart. Rapid breathing and 
heart action are usually associated with coughs. (See explanation of how spinal lesions produce 
perverted physiological efiects in Part II.) 



GENERAL AND OSTEOPATHIC. 69 

gray matter of the spinal cord, from the second thoracic to the 
third lumbar segments, inclusive. Fibers (axones) pass from 
these cells to the lateral chain ganglia or to peripheral plexuses 
as pre-ganglionic fibers. The post-ganglionic fibers pass from 
the point of termination of the pre-ganglionic fiber to the muscles 
of arteries supplied. 




Fig. 7. — The upper line in this tracing shows the result of stimulation of the central end 
of the sciatic after an artificial bony lesion had been produced in the mid-dorsal region. It will 
be seen by referring to Figs. 4 and 5 that this is just the opposite from the normal reaction 
which should have occurred. The lower tracing shows the normal changes before lesion. 

Vaso-constrictor fibers are to be found in nearly all nerve 
trunks, both spinal and autonomic. Those nerve trunks — the 
splanchnics, which supply the abdominal and pelvic viscera, 
and the spinal nerves which supply the skin — are especially rich 
in vaso-constrictor fibers. The spinal nerve trunks which carry 
vaso-constrictors to skin surfaces, arteries of the muscles, etc., 
also carry other autonomic fibers, such as fibers to the sweat 
glands (secretory); pilomotor fibers to the muscles of the skin, 
and possibly others. In the spinal autonomics, which supply 
fibers to the abdominal and thoracic viscera, there are many 
other fibers carried along in the same nerve trunk with the vaso- 
constrictors, such as accelerators to the heart; augmentors to the 
heart; pupillo-dilators ; viscero-motors and probably some secre- 
tory fibers. As may be seen from Plates II and III, the axones 
pass out by the anterior spinal root to some of the ganglia of the 
lateral chain. These are the white rami communicantes. After 
having reached the lateral chain, these fibres 1. may terminate 
about a cell body of the first ganglion reached, or 2. they may 



70 



PHYSIOLOGY : 



pass up or down the lateral chain to terminate in some other 
ganglion; or 3. they may pass beyond the lateral chain to some 
peripheral ganglion; 4. the post-ganglionic fibers which are 
supplied to skin and the arteries of muscles, etc., originate from 
cells in the lateral chain, pass back and are distributed with the 
spinal nerves. These are the gray rami communicantes; 5. there 
are other fibers which pass back and supply the arteries of the 
meninges of the cord. 



gfMNM^ 



j&s&C* 



Fig. 8. — This tracing shows the result of osteopathic stimulation applied to the upper 
dorsal regions of the spine in the dog. It will be noted that a marked increase in blood pressure 
occurred during the time of stimulation, which immediately dropped as soon as the stimulation 
was discontinued. 

Structures Supplied by Vaso-Constrictors. — There are 
only three important structures of the body — the brain, the 
lungs and the heart — to which vasomotor fibers of one kind or 
the other have not been demonstrated. Whether or not these 
organs receive vasomotor nerve fibers is yet a question which 
future research work may decide. 

It has been shown by Martin that the stimulation of the 
vagus causes dilation of the arteries on the surface of the heart. 
There is other experimental evidence in favor of the existence of 
vasomotor fibers to the heart, both constrictors and dilators, 
but nothing has been conclusively proven. 

Blood Supply to the Brain. — Since the brain, a soft struct- 
ure, is contained within the very rigid walls of the cranium, expan- 
sions and contractions caused by extreme variations cannot be 
compensated for by extension, as in most other body structures. 
This condition would seem to demand a different circulatory 
mechanism than that which exists in other organs. The two 
vertebral arteries and the two internal carotids, which form the 
circle of Willis, constitute the arterial supply to the brain. The 



GENERAL AND OSTEOPATHIC. 



71 



arrangement of the blood supply is such that the circulation to 
the brain would not be easily disturbed by an interference with 
one artery, but in some instances the occlusion or even a compres- 
sion of these arteries is followed by physiological perversions. 
"In some animals, the dog, one can ligate both internal carotids 
and both vertebra] s without causing unconsciousness or the 
death of the animal. In an animal under these conditions a 
collateral circulation must be brought into play through the 
anastomoses of the spinal arteries. In man, on the contrary, it 
is stated that ligation of both carotids is dangerous or fatal." 
(Howell.) 

The author has found that ligation or even temporary com- 
pression of the carotid arteries in cats results in marked varia- 
tions in physiological functions of the brain. If, for example, 
after the two carotids are ligated the ether be discontinued, the 
animal will often not regain consciousness, or temporary com- 
pression of the carotids may be made to take the place of the 
anesthetic. This shows only the immediate effects of an obstruct- 
ive interference with the blood supply to the brain. What the 
result would be of a long-standing or permanent partial inter- 
ference would be has never been experimentally determined, but 
it is safe to say that no disturbance of such a nature could exist 
without resulting in some perversion of the functions of the brain. 
There is much good clinical evidence to show that bony lesions 
often produce such effects. 



or 



H ***3 Pre* 






Fig. 9. — This tracing shows the result of heavy pressure stimulation applied to the upper 
dorsal region . of the spine. It will be noted, as shown in No. 1 of the tracing, that a marked 
increase in blood pressure resulted, which remained three millimeters above the base line after 
the drum had made a complete revolution. This shows the permanence of the effects of the 
stimulation. By referring to Figs. 8 and 9 it will be seen that pressure and manipulation pro- 
duce practically the same effects on blood-pressure changes. 



72 PHYSIOLOGY : 

The venous drainage of the brain is effected chiefly by way 
of the venous sinuses, which are spaces between the folds of dura 
mater or between the dura and the skull bones. These sinuses 
receive the cerebral veins and veins from the bones of the skull, 
pia mater, and dura mater. The greater part of the venous blood 
is drained into the internal jugular veins from the lateral sinuses, 
but some of it is drained into the ophthalmic veins and some into 
the venous plexuses of the spinal cord and its meninges. Since 
the cerebrospinal fluid, its formation and drainage has much to 
do with the regulation of intracranial pressure, the reader is 
referred to that subject. 

Any increase in systemic blood pressure is followed by an 
increase in intracranial pressure and an increase in the actual 
amount of blood flowing through the brain. The physiological 
effects of this increased supply of blood and the increased blood 
pressure are not well known. 

It is not known whether or not the arteries of the brain are 
supplied with vasomotor nerve fibers, but the general opinion of 
those research workers who have tried to determine this question 
is that these vessels have no such provision. 

Vaso-Constrictors to the Head and Neck. — The vaso- 
constrictor nerve supply to various structures of the head, such 
as the skin, the mucous membranes of the mouth and eyes, and 
the glands of the mouth and neck, are derived from the cervical 
portion of the spinal autonomics. The pre-ganglionic fibers 
arise from the upper thoracic segments of the cord, pass upwards 
in the lateral chain, and terminate chiefly in the superior cervical 
ganglion. From here the post-ganglionic fibers are distributed 
to the various structures supplied by various paths, but they 
usually follow the arteries that supply the structures. In some 
cases it has been shown that both constrictor and dilator fibers 
follow the same course, which is the path of some cervical or 
cranial nerve. 

Vaso-Constrictors to the Upper Limbs. — The fibers 
supplying the upper limbs originate from the mid and upper 
thoracic regions of the cord, and are distributed from the ganglia 



FACIAL IYERVE 
BASILAR ARTERY 

1st CERVICAL NERVE 
GREAT OCCIPITAL NERVE 
2d CERV. NERVE 
EXT. CAROTID 
SUP CERV. GANG LI OH 



EX TE RIVAL CA RO TIP 
SCALENUS MEDIUS MUSCLE 



MID. CERV GANGLION 



PHRENIC /VERVE 
AT PNEUMO /VERVE 

VERTEBRAL ARTERY 

TEI7H"L JUGULAR VE//V 

C/JLENUS AHT/CUS rtUJCLE 

BRACHIAL PLEXUS 
SCALENUS POSTICUS MUSCLE 

fzT RIBfDRAUN UPWARD) 
2d Rl0(PRA WN UPWARD) 
/jT INTERCOSTAL NERVE 
Ijl AORTIC IN TEA COSTAL ARTERY 

INTERNAL MAMMARY VESSELS 
AORTA 
2d INTERCOSTAL TVERVE 
LATERAL CUTANEOUS NERVE 




'HTtRCOSTAL NERVES 



SOLAR PLEXUS 



5 UP MESENTERIC ARTERY 



LAST THORACIC 



trlFERlOR VETiA CAVA 
SYMP. CHAlTi 



LUMBAR Pi EX US 



Plate VII.— Showing heart, aorta, and some of its branches, including arteries to the neck 
and tace, also the intercostal vessels. Notice that the vessels are surrounded by nerves from 
the sympathetic chain which control their size. Bv referring to plates II, III, and IV the 
connections of these nerves with the spinal cord mar be seen. 



I 






GENERAL AND OSTEOPATHIC. 73 

of the lateral chain by way of the spinal nerves t,o the skin, and 
probably to the muscles and joints. 

The fibers supplying the skin of the trunk come from the 
thoracic portions of the lateral chain, and are supplied with spinal 
nerves to the various parts. 

The fibers supplying the lower limbs originate from the 
lower thoracic and upper lumbar portions of the lateral chain, 
and are distributed with the spinal nerves as in case of the ones 
described above. 

Vaso-Constrictor Supply to the Abdominal Viscera. — 
These fibers are to be found in the splanchnic nerves, and are 
derived from the fifth to the twelfth thoracic segments of the cord, 
inclusively. Some may come from the first and second lumbar 
segments of the spinal cord. They supply the following struct- 
ures: 1. The arteries of the mesentery from the oesophagus to 
the descending colon; 2. the pancreas; 3. the kidneys; 4. the 
spleen; 5. possibly the liver. The stomach receives its vaso- 
motor supply from the fifth to ninth thoracic segments of the 
cord. The fibers supplying the intestines originate from all of 
the spinal autonomics from the fifth thoracic to the second lumbar, 
inclusive. The liver receives its splanchnic (viscero-motor and 
possibly secretory and trophic) from the seventh, eighth, and 
ninth spinal segments, and there is some experimental evidence 
to show that it receives vaso-constrictor fibers from this source. 
Some authorities claim that the vaso-constrictors of the liver 
originate from the eleventh and twelfth thoracic segments. The 
pancreas receives its vaso-constrictor supply from about the same 
region as the liver. Since these structures, the liver and the 
pancreas, are developed from the alimentary tube, they may be 
expected to have the same common nerve supply, and they do. 
The vagus supplies these structures with secretory fibers (they 
have been demonstrated to the pancreas but not yet to the liver), 
probably trophic, and possibly vaso-dilator fibers. 

The kidneys receive their vaso-constrictors from the eleventh 
and twelfth thoracic segments of the cord, and they may possibly 
get some fibers from the upper lumbar segments. From the 



74 



PHYSIOLOGY : 



results of Series No. 16 (See Part II), it would seem that these 
fibers are also secretory. Some authors claim that vaso-dilator 
fibers to the kidneys may also be found in these nerves. 

The vaso-constrictor fibers supplying the spleen originate 
from the sixth, seventh, and eighth thoracic segments of the 
spinal cord. These fibers (pre-ganglionic portions) originate 
from cell bodies lying in the antero-lateral part of the gray matter 
of the cord of the different segments named, and pass out by 
way of the anterior root to the lateral chain. Some of the axones 
of the pre-ganglionic fibers end immediately in the ganglia of 
the lateral chain. Some pass up or down one or more segments 
and terminate about cell bodies, and some are distributed beyond 
the lateral chain to the prevertebral plexuses. Other fibers 
(the post-ganglionic fibers) arise from the point of termination of 
the pre-ganglionic fibers, and are distributed to the vessels of the 
viscera supplied. 



$fr -^^«^t^C^>W^5L7^€^ *>£«t~ GL+tt*' 



Fig. 10. — This tracing shows the result of artificial flexion, while maintaining a fixed 
point in the upper dorsal region of the dog. It will be seen that this lesion produced a marked 
increase in blood pressure (12 millimeters of mercury) as a result of the abnormal stimulation 
produced. 

Vasomotor Supply to the Pelvic Viscera. — Fibers of this 
system (pre-ganglionic) arise from the upper lumbar and possibly 
the lower thoracic segments of the cord. Post-ganglionic fibers 
are distributed by way of or from the inferior mesenteric ganglia, 
and the hypogastric nerves to the arteries of the uterus, vagina, 
bladder, and rectum. In the male they supply the seminal 
vesicles, vas deferens, testicles, and prostate glands, in addition 
to the bladder and rectum. 



GENERAL AND OSTEOPATHIC. 



75 



Vaso-Constrictors to the Genital Organs. — These fibers 
arise from the lower thoracic and upper lumbar segments of the 
spinal cord, and pass from the lateral chain by way of the hypo- 
gastric nerves or by way of the sacral autonomic ganglia to the 
pudic nerves. These fibers supply vaso-constrictor fibers to the 
penis and scrotum in the male, and the clitoris and vulva in the 
female. The vaso-dilators to these parts are described under the 
distribution of the dilator fibers. 




Fig. 11. — This tracing shows a marked decrease in blood pressure resulting from an artifi- 
cial bony lesion produced in the lower dorsal region of the dog; further showing that perverted 
physiological conditions of the circulatory regulating apparatus can be caused by bony lesions. 
The result is due to vaso-dilation. 

The Vaso- Dilators. — The general methods of demonstrating 
the presence of vaso-constrictor fibers, as explained above, are 
also used for demonstrating the presence of vaso-dilators. 

The vaso-dilators differ from the vaso-constrictors in certain 
respects in their physiological action, as follows: 1. The vaso- 
dilators do not seem to exert a constant tonic activity on the 
structures supplied, as do the constrictors; 2. Their action is 
effected reflexly in some instances at least, only during the time of 
demanded functional activity of the structures which they supply. 
The dilators of the salivary glands, for example, are active only 
during the period when secretion is most active, and the same 
condition obtains in case of the dilators to the penis. 

The following groups of vaso-dilator fibers have been posi- 
tively determined, and it is quite probable that future research 
will result in the finding of others. It has seemed most logical to 
group these fibers into two general classes, viz., those which are 
distributed with the cranial nerves and their subdivisions, and 
those which originate with the lateral chain ganglia and their 
subdivisions. 



7(5 physiology: H! 

The Cranial Autonomic Dilators.— These fibers are dis- 
tributed with certain cranial nerves as follows: 1. The dilator 
fibers distributed with the chorda tympani branch of the seventh 
cranial nerve supply the submaxillary and sublingual salivary 
glands and the anterior two-thirds portion of the tongue; 2. Those 
fibers distributed with the tympanic branch of the ninth cranial 
nerve supply the parotid gland, the mucous membranes of the 
pharynx, the tonsils and the posterior one-third portion of the 
tongue. 




Fig. 12. — This tracing shows the result of an artificial osteopathic lesion produced in the 
upper dorsal region of the spine. It will be noted that as the result of this lesion an increase 
in blood pressure resulted, which became normal after the perverted condition of the spine (the 
artificial lesion) was normalized. It therefore shows that an artificial bony lesion may produce 
abnormal effects on the regulatory apparatus of the rate of the heart beat and blood pressure. 

The Spinal Autonomic Dilators. — These fibers may be 
classed into two general groups, as follows: 1. Those originating 
from the cervical spinal autonomics are distributed to the mucous 
membranes of the lips, the palate, the gums, the nasal cavities 
and the skin of the cheeks; 2. It is thought by some authorities 
that vaso-dilators have been demonstrated to exist in the thoracic 
autonomics which supply the abdominal viscera. These fibers 
pass by way of the splanchnic nerves; 3. There is also good 
reason to believe that vaso-dilator fibers from the thoracic spinal 
autonomics are distributed to the limbs and other somatic parts 
by way of the spinal nerves of the brachial and lumbar plexuses, 
in the same way as the vaso-constrictors are supplied to these 
structures; 4. It has been definitely shown that a group of vaso- 
dilators are distributed to the external genitals from the second, 
third, and fourth sacral segments. These fibers rise from the 
second, third, and fourth sacral spinal nerves, and pass from here 
to the hypogastric plexus. This group of fibers is known as the 
nervi erigentes. It has been shown that the erection of the penis 
is caused by these fibers. 



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i tbtunifor Vessels 



GENERAL AND OSTEOPATHIC. 77 

Nature of the Action of Vaso-Dilators. — In the case of 
the vaso-constrictors, it is easy to understand how the contraction 
of the circular musculature of the arteries would cause a decrease 
in the lumina of the vessels, but it is not so easy to understand 
how a condition of dilation could be caused by the stimulus of 
the nerves. One explanation is that the stimulus by way of the 
dilators inhibits the tonic action of the constrictors, and in this 
way vaso-dilation is caused indirectly. Another explanation is 
that some difference in the nature of the stimulus to the fibers 
may determine the nature of the effect produced. Still another 
theory is that the action of the dilators may be explained by a 
possible function of inhibition which the dilator fibers influence 
upon certain constrictor centers, which reduces the tonic action 
of the constrictors, thus causing dilation indirectly. 

Parts of Vascular System Supplied by Vasomotors. — 
It is generally considered that the vasomotors, both constrictors 
and dilators, end in the muscles of the small arteries, and these 
parts are therefore affected most by vasomotor control. It can 
readily be seen that the small arteries, since they furnish directly 
the supply of blood to the various structures, should receive the 
nerves which regulate the amount of blood supplied. The large 
arteries do not have the property of dilation and constriction as 
do the smaller arteries, and they have few or no vasomotor fibers. 

It has been demonstrated that some parts of the venous 
system have vasomotor fibers. Mall has shown that the veins 
of the portal system receive vaso-constrictor fibers, but other 
than this it caimot be said that venomotor nerves have been 
demonstrated. 



CHAPTER VII. 

THE FLOW OF BLOOD THROUGH THE 
VASCULAR SYSTEM. 

If the web of a living frog's foot be fastened under the objec- 
tive of a microscope the flow of blood may easily be observed. 
By this means the nature of the flow in the arteries, veins, and 
capillaries may be studied. It may be seen that the blood moves 
much more slowly in the capillaries than in the arteries, and that 
there is no evidence of pulsations. In the arteries and veins 
the corpuscles are held in the midportion of the stream and con- 
stitute what is known as the "axial current," while that part 
about the axial current, the so-called " inert layer," contains 
the plasma. 

Circulation Time. — The time required for one complete 
circulation, that is, the time necessary for a particle of blood to 
pass from any one point of the circulatory stream through the 
system and back to that point of the circuit, is twenty-three 
seconds, which requires from twenty-five to thirty heart beats. 
This varies, of course, with the route through the circulatory 
system, so this figure is given only as an average. Various 
methods have been used for determining this, but the method 
used by Hering is probably the one most generally applied. It 
was done by injecting potassium ferrocyanid into the jugular 
vein of one side, and testing the contents of the jugular vein of 
the other side to determine the length of time necessary for its 
appearance there. 

Velocity of Blood Flow. — The velocity of the flow r of blood 
varies materially with the kind of vessel through which it is pass- 
ing, the flow being most rapid in the large arteries near the heart 
and gradually decreasing as it approaches the capillaries. The 
78 






GENERAL AND OSTEOPATHIC. 79 

flow of blood in the arteries is not regular, but varies with the 
heart beat from 150 millimeters per second during diastole to as 
much as 520 millimeters per second during systole. 

In the veins the blood flow is regular, but is much less rapid 
than in the arteries. The velocity of blood flow in the large veins 
varies from 60 millimeters to 150 millimeters per second. 

In the capillaries the blood flow is regular like that of the 
veins, but the velocity is very much less, being only about one 
millimeter per second. 

Variations in Velocity of Blood Flow. — The velocity of 
the blood in the arteries varies inversely with the distance from 
the heart, i. e., the velocity decreases as it approaches the capil- 
laries. This decrease in velocity is caused by the loss of pres- 
sure from the heart as the distance from the heart increases, and 
also by the increase in the area of the blood bed, the total cross 
section of the small arteries being greater than the larger artery 
of which they are branches. This factor is much more effective 
in causing the reduced pressure in the capillaries, as the total 
cross section of the capillaries is estimated to be about eight 
hundred times that of the aorta, and the velocity and pressure 
are reduced in proportion. 

The heart beat also influences the velocity and pressure of 
the blood in the vessels. Anything which causes an increase 
of heart beat affecting both rate and amplitude, increases the 
blood flow in proportion to this increase. Conversely, it may be 
stated that any decrease in the force or rate of heart beat corre- 
spondingly reduces the velocity and pressure of the blood. 

The blood pressure and velocity are both influenced by the 
size of the small arteries, as affected by the vasomotor nerves, 
vaso-constriction causing an increase in blood pressure and a 
corresponding decrease in velocity, as it will decrease the total 
amount of blood passing from the small arteries into the capil- 
laries and to the veins. The converse of this statement is also 
true, viz., that vaso-dilation will cause a decrease in blood pres- 
sure, an increase in the velocity, and an increase in the total 



80 physiology: 

amount of blood passing from the small arteries to the veins by 
way of the capillaries. 

There is very little if any variation in the size of the capil- 
laries from any cause. The velocity and pressure in these vessels 
therefore depends upon the variations in pressure and velocity 
of the blood in the arteries, of which the capillaries are branches, 
and the veins in which they terminate. The capillaries are com- 
paratively very short, and the velocity and pressure are both 
very low. The greatest amount of change of gases from blood 
to tissue and from tissue to blood occurs through the walls of the 
capillaries. 

Blood Pressure. — : The blood pressure is greatest in the 
arteries, varying from 150 millimeters of mercury in the aorta 
to 110 millimeters or 120 millimeters of mercury in the brachial 
artery, and continues to decrease toward the periphery. During 
diastole of the heart the pressure is from 40 millimeters to 50 
millimeters of mercury less than during systole. During 
diastole the pressure in the brachial artery is reduced to from 
65 millimeters to 75 millimeters of mercury. This difference in 
the blood pressure in the arteries is known as the pulse pressure. 
The blood pressure in the veins is much less than in the arteries, 
being greatest in the peripheral veins and decreasing as it 
approaches the heart. In the peripheral veins the pressure 
varies from 2 millimeters to 10 millimeters or more of mercury, 
depending upon the location of the vein, its course, etc. In the 
inferior vena cava the pressure varies from nothing to 2 milli- 
meters to 3 millimeters of mercury. The blood pressure in the 
veins varies somewhat with the position of the body, but there 
are no pulsations as in the arteries. 

The blood pressure in the capillaries varies from 20 milli- 
meters to 40 millimeters of mercury, depending upon the pressure 
in the small arteries, the systemic blood pressure, and the pressure 
in the veins. The flow through the capillaries is regular, as in 
the veins. 

Methods of Study. — The blood pressure in the arteries was 
first studied (Hales, 1733) by attaching an artery of a horse to a 



GENERAL AND OSTEOPATHIC. 



81 




82 physiology: 

perpendicular glass tube, in which the blood arose to a height 
of eight feet and three inches. In a tube attached to a vein the 
pressure caused the blood to rise only to twelve inches. 

Modern methods of measuring blood pressures consist of 
the use of certain instruments in which the pressure of the blood 
acts upon a mercury column. For mammalian work the pres- 
sure of the blood is taken from an artery (usually the carotid or 
femoral) by ligating a three-way glass cannula into the central 
end of an artery. Another arm of the cannula is connected to a 
tube leading from a container suspended from three to four feet 
above the animal. Through the tube leading from this container 
some fluid (10% sodium citrate) is allowed to flow, filling the 
bulb of the cannula before the artery clamp is removed from the 
artery. The third arm of the cannula is attached to a mercury 
manometer, which consists of a U tube partly filled with mercury. 
From the open end of the U tube a pointer extends from a float 
on the surface of the mercury. The manometer is adjusted so 
the pointer may be made to write on the smoked paper of a 
kymograph, and in this way the blood pressure and pulse varia- 
tions may be recorded. If the two columns of mercury in the U 
tube of the manometer are level when the clamp is removed from 
the artery and the tube leading from the citrate bottle is closed, 
the rise of mercury in the open arm of the tube above the level 
in the closed arm will represent the amount of blood pressure in 
millimeters of mercury. 

For the purpose of determining the blood pressure in the 
large arteries of the human, another instrument, the sphygmo- 
manometer, is used, of which there are now many good makes 
obtainable for clinical use. 

Systolic and Diastolic Variations. — By observing the 
surface of the mercury column in the manometer when it is 
attached to an artery of a living animal, or by observing the 
tracings so made, it will be seen that variations in the blood pres- 
sure occur regularly at intervals, and that these intervals corre- 
spond exactly with the heart beats. During systole (in the dog) 
the mercury rises from 20 millimeters to 40 millimeters of mercury 



GENERAL AND OSTEOPATHIC. 



83 




Fig. 14. — This figure shows a modern kymograph, which is used for recording blood pres- 
sure and respiratory tracings. The tracing is made by a writing point, which records the 
result on a smoked paper attached about the drum of the kymograph while the drum revolves. 
See Fig. 13. 



84 PHYSIOLOGY : 

higher than its lowest or diastolic level. In man this variation 
amounts to from 40 millimeters to 50 millimeters of mercury when 
taken from the brachial artery, which is known as the pulse pres- 
sure. The amount of pulse pressure is greatest in the large arteries 
near the heart, and decreases as the distance from the heart 
increases, until there is very little pressure in the small arteries. 
There is no pulse pressure in the capillaries and veins. 

The average or mean blood pressure in the arteries is obtained 
by taking the average of the systolic and diastolic pressures. It 
is the diastolic pressure plus one-half the pulse pressure, or it 
is the systolic pressure minus one-half the pulse pressure. 

Normal Blood Pressure. — The sphygmomanometer is 
the instrument most commonly used for determining the arterial 
blood pressure in man. As has been stated, the normal blood 
pressure in the adult man taken from the brachial artery is sub- 
ject to much variation, the difference being caused by pulse 
pressure, but the average systolic blood pressure varies between 
110 millimeters and 145 millimeters of mercury (Faught). The 
average pressure in the brachial artery for young adults (20 to 
25) is stated as 110 millimeters of mercury (Erlanger). 

Blood- Pressure Variations.— The arterial blood pressure 
varies directly with age, being from 80 millimeters to 100 milli- 
meters in children; 110 millimeters to 145 millimeters in adults, 
and from this it may go as high as 200 millimeters or even more 
in old age. The pressure is usually from 8 millimeters to 10 
millimeters less in women than in men. There are also daily 
variations such as those caused by the taking of food; by sleeping 
or by muscular exercise. During and after sleep or any kind of 
physical and mental rest the blood pressure is much reduced, 
while after exercise or after a meal the blood pressure is much 
increased. It can readily be seen why the pressure should 
increase from muscular exercise, but the causes of an increase 
after a meal are not so readily understood. It would seem that 
since there is such a marked dilation of the vessels of the splanch- 
nic area (stomach and intestines), the systemic blood pressure 
would be decreased in proportion. If this should follow with 



GENERAL AND OSTEOPATHIC. 85 

no compensation, other organs would necessarily suffer from a 
diminished supply. It seems that this splanchnic dilation is 
compensated for by an increased activity on the part of the heart, 
and it will usually be found that blood pressure after a meal is 
much increased and there is constantly an increase in the pulse 
pressure, showing that the heart is beating more forcefully. 

THE PULSE. 

When the ventricles contract, throwing the blood with great 
force into the arteries, this force is not transmitted directly, but 
gradually to the peripheral arteries. As the blood enters the 
arteries from the ventricles they dilate from the force created by 
the contraction of the ventricles, and gradually resume their 
original size by virtue of their elasticity. This causes a gradual 
pressure to be exerted upon the blood contained in the arteries, 
and since the closed valve prevents a back flow into the heart, a 
wave of blood is forced toward the capillaries. This graduated 
force caused by the extensibility and elasticity of the arteries is 
responsible for the regularly distributed pressure of the blood 
throughout the vascular system. 

When the ventricle contracts and the quantity of new blood 
is thrown into the aorta, it extends to give room for the increased 
quantity of blood. After the ventricle has ceased to contract 
and the walls of the aorta begin to resume their original size by 
virtue of their elasticity, the column of blood is forced toward the 
capillaries, as the closed semilunar valve prevents its backward 
flow. This flow of blood from the heart towards the periphery 
is known as the pulse wave, and its velocity varies inversely with 
the extensibility of the arterial walls. If the walls of the arteries 
are hardened (sclerosis) the pulse wave is transmitted much 
faster and the blood pressure is increased. The velocity of the 
pulse wave in normal individuals varies from six to ten meters 
per second. In old individuals in case of sclerotic arteries or 
cardiac hypertrophy, or both, the velocity of the pulse wave may 
be as high as ten to fourteen meters per second. 



I 



86 physiology: 

The Sphygmograph and Sphygmogram. — The sphyg- 
mograph is an instrument used for making tracings of the 
pulse wave, and the tracing so made on smoked paper is known 
as the sphygmogram. The instrument is attached to the wrist 
in such a way that the pulsations of the radial artery are trans- 
mitted to a writing lever, which makes the tracing on the strip 
of smoked paper as it passes beneath the writing lever. The 
curve produced by the writing lever and caused by the pulse wave 
consists of two parts, viz., the ascending or anacrotic limb, and 
the descending or catacrotic limb. 

The Anacrotic Limb. — The ascending limb is produced 
by the sudden impact of blood, which lifts the lever quickly, 
causing a sudden upstroke. This does not accurately represent 
the wave, as the apex of the curve is proportionately too high and 
too sharp. This sharp, high apex is due to a mechanical error, 
the " fling" of the lever, and does not represent the real form of 
the pulse wave. The anacrotic limb normally shows no varia- 
tions, which means that there is a gradual unvarying rise in the 
pulse wave which causes it. Under certain pathological condi- 
tions of the heart, as in stenosis of the aortic valve, a notch may 
be produced in the ascending limb which is known, as the anacrotic 
notch. This is never present in normal pulse waves. 

The Catacrotic Limb. — The descending or catacrotic 
limb is formed during diastole, and represents the gradual descent 
of the pulse wave. The catacrotic limb, unlike the anacrotic 
limb, is not a regular curve but shows one or more secondary 
curves or notches. The most marked of these secondary curves 
is the one to be observed about the mid portion of the descending 
limb, and is known as the " dicrotic wave." Occasionally a less 
prominent wave between this and the apex, the " pre-dicrotic 
wave," may be found. 

Post-dicrotic waves are described as following the dicrotic 
wave, but they are certainly not common. These waves cannot 
ordinarily be felt in the normal pulse, but the dicrotic wave may 
sometimes be palpable by the physician or nurse with a highly 
sensitive touch. The dicrotic wave is often accentuated in 



GENEKAL AND OSTEOPATHIC. 87 

those conditions in which the muscle tone of the walls of the 
arteries becomes much reduced and the blood pressure becomes 
low. The dicrotic pulse is often a diagnostic sign of typhoid 
fever, and may occasionally be found in other infectious diseases. 
To the palpating finger it feels like two beats occuring in the time 
of one, the second being less marked than the first. 

Causes of the Dicrotic Wave. — Many explanations have 
been offered, but there seems to be no doubt that the following 
is correct: The closure of the semilunar valves after systole 
of the ventricles is followed by tendency of the blood to flow 
back into the ventricle, but this is suddenly checked and the recoil 
thus produced sets up a second wave which follows the primary 
pulse wave, and causes a second slight rise in the pulse wave 
during the descent of the first wave. It may be readily shown 
by producing a wave in a pan, or better, a trough of water, that 
the wave nearest the side is reflected in the form of one or more 
secondary waves which follow the first wave produced, and which 
move in the same direction with the same velocity. This sec- 
ondary wave in the normal artery is inconsiderable, but in those 
abnormal conditions in which the arterial wall is less resistive 
and the blood pressure is low from peripheral resistance, the 
secondary pulse wave may be able to cause a perceptible rise, 
which is the cause of the dicrotic pulse. There are many other 
conditions of variation in the nature of the pulse wave besides 
these given, but they occur only under abnormal conditions and 
belong, therefore, in a course on physical diagnosis. 

Heart Sounds. — The sounds produced by the normally 
functioning heart are two in number, the first or "lubb" sound 
occurring at the beginning and the other, the "dup" sound, 
occurring at the end of the ventricular contraction or systole. 
The first sound is caused chiefly by the closure of the auriculo- 
ventricular valves (mitral and tricuspid), but the contraction of 
the musculature of the ventricles is also causative of the sound. 
We may divide the sound into two factors, viz., the valvular 
element and the muscular element. 



88 PHYSIOLOGY : 

The second heart sound, the "dup, " is a much shorter and 
sharper note than the first, and is caused by the closure of the 
semilunar valves and the vibrations set up by the valves trans- 
mitted to the chest wall. That this is the cause of the second 
heart sound has been shown by holding the valve flaps apart 
with a wire hook while the heart was beating, in which case no 
sound was produced, and in various other ways the same cause 
has been shown to be true. 

A third heart sound is sometimes given, which is said to 
occur very promptly after the second sound, but this can surely 
not be heard in the average individual. It seems to be audible 
only in certain cases, and the most delicate apparatus is neces- 
sary for its detection. The cause or nature of this sound is 
unknown. 

The clinical value of the heart sounds, while of very great 
importance, belongs more properly in a course on physical diag- 
nosis, and will therefore be only very briefly given here. Since 
it is known that the valves of the heart are continuous with the 
endocardium, it would be natural to assume that any affection 
of the endocardium would involve the heart valves, causing them 
to fail in their proper functions. Inflammation of the endo- 
cardium is often followed or accompanied by " murmurs" or 
imperfect sounds, due to imperfect closure of the auriculo- 
ventricular valves. Any condition of overstrain, etc., which 
results in dilation or hypertrophy of the ventricles, also pre- 
vents the proper closure, and mitral or tricuspid " murmurs' ' 
result. The mitral valve is most commonly affected because of 
the greater pressure on the left side of the heart. In case of a 
failure in closure of the mitral valve (mitral insufficiency) there 
occurs at the time of ventricular systole a back flow of blood into 
the left auricle, and this, meeting the flow from the pulmonary 
veins, causes a low murmur following the first sound of the heart. 
If the left ventricle grows sufficiently (hypertrophies) to main- 
tain a normal blood pressure, regardless of this leakage, there may 
be no harmful results. If this does not occur the back pressure 
in the lungs and on around to the right heart may cause a failure 






THYROID GLAND 

R Subclavian artery 

<?«/ THOR VERTEBRA ROTATED 

pmeumooastric he rive 
rt. intiom RR t 



LEFT /tirtOM ART 

AORT/\ 

DEEP card PLEXUS 
OANCL OF WRiSDERO 
SUPERFICIAL CARD PLEXUS. 



I coronary plea 

RT. CORONARY PLEX 
7lh THOR VERT, ROTATED 



E SOPHAOEAL PLE'US 



OlAPHRRGrl 
L PNEUMOGASTRic N 

COR (GASTRIC) PLEA. 

RT PNEUNO nCRVE 

GT. SPLlnCHHIC TlERVE 

JTOT1ACH 



llth THOR VERT, ROTATED 
L SEMILUNAR OAfiG 
RT SEM/LuflAR OA11G 

SUP MESENTERIC GAIYG. 

LAST THOR C AUG. 

RE HAL GANOL. 

SMALLEST SPLANCHNIC N. 

ifc/vAL Plexus 




SUP MESEHTERIC PLEXUS 
HT LUMBAR GANG. 

24 LUMBAR VERT ROTATED 

AORTIC PLEX. 

GANGLIA TED CORD of N>e SYM 

INF. VENA CAVA 

LUMBAR NERVES 

SMALL INTEST/r/E. 



IMF ME SEN TERIC PLE X . 



HYPOGASTRIC PLEX 



PEL VIC PLEX 
ANT. CRURAL tl. 
OT. SCIATIC NERVE 



MID. HEMORRHOIDAL . PLEX 



FET1URRL ARTERY 
VB5/CRL PLEXUS 



Plate IX — The nerves of the heart and blood vessels. Several spinal lesions are indi- 
cated showing disturbance of the nerves supplying internal blood vessels going to the stomach, 
bowels, etc. 



- 






■ 



GENERAL AND OSTEOPATHIC. 



89 



of the right heart to drain the venous blood from the system, and 
the collection of extravascular fluid in the tissues, or dropsy, may 
follow. 

Other conditions , such as stenosis or narrowing of the lumen 
of a valve, may occur, which increases the resistance to the blood 
flow through the valve, and because of this increased resistance 
greater work is demanded of the musculature of the heart and 
dilation Jor hypertrophy results. 




Fig. 15. — This figure shows an induction coil, which is used for applying the electrical 
stimulation to nerve trunks and other structures. 



The Cardiac Impulse. — In most normal chests careful 
inspection will reveal an impulse occurring with each ventricular 
systole at a point (in adults) internal to and below the nipple in 
the fifth intercostal space. This is known to physiologists and 
clinicians as the apex impulse, apex beat, or point of maximum 
impulse, commonly termed the P. M. I. "It is now generally 
admitted that the 'apex impulse' is caused by the impact of a 
portion of the right ventricle against the chest wall, and not by 
the apex of the heart itself." It is not the downward pressure 
of the heart against the chest wall caused by the systole that 



90 



PHYSIOLOGY : 



causes the apex beat, as was originally supposed, as during 
contraction of the ventricles they thicken and shorten, and this 
would tend to draw the heart away from the chest wall. There 
are probably three factors causative of the apex beat: First, 
the hardening of the walls of the ventricles, which makes them 
more resistant and capable of forcing the chest wall outward; 
second, the partial rotation of the heart during systole tends to 
hold it against the chest wall; and third, the tendency of the 
curved portion of the aorta to straighten when the volume of 
blood is forced into it from the left ventricle, forcing the heart 
downward and outward. 



CHAPTER VIII. 

PHYSICAL FACTORS INVOLVED IN 
CIRCULATION. 

Causes of Blood Flow. — The chief cause of the flow of the 
blood through the system is the heart beat. Variations of the 
rate and amplitude of the heart beat therefore modify the velocity 
of the blood flow and the blood pressure, the velocity of flow and 
pressure varying directly with the rate and force of the heart beat. 
It must be understood, however, that any increase in the rate of 
heart beat does not always mean an increase in the velocit}^ of 
blood flow or the blood pressure, as there may be a rapid heart 
beat with a decreased amplitude or with a decreased vascular 
tone, which would result in vaso-dilation and a decreased blood 
pressure. 

Accessory Causative Factors in Blood Flow. — There 
are many factors other than the force and rate of the heart beat 
that materially influence the flow of blood through the vascular 
system, as follows : 1 . Variations in the elasticity of the walls 
of the arteries have much to do with the blood flow, as it is the 
recoil of the arterial walls that furnishes the force to the blood 
after the force from the systole of the heart has been lost. The 
elastic artery, then, is one of the important causative factors in 
normal flow, and any variation from this condition must influence 
the flow. If the walls of the arteries become hardened and their 
elasticity reduced or lost the blood pressure is much increased, 
and the opposite condition obtains if the walls of the arteries 
lose their tone and become flabby. In certain infectious fevers, 
typhoid for example, the musculature of the arteries becomes 
very lax and the blood pressure is reduced. A second pulse 
beat can often be felt because the artery is so flaccid that the 

91 



92 PHYSIOLOGY : 

second wave is felt following the first, and the condition is known 
as a dicrotic pulse; 2. Pressure of contracting muscles, the force 
of which is exerted upon the veins and capillaries, is another 
factor that influences the blood flow in these vessels. Muscular 
exercise therefore aids circulation indirectly; 3. The movements 
of respiration also influence the flow of blood by causing varia- 
tions of pressure in the thoracic cavity, which effect the flow of 
blood towards the heart by decreasing the pressure in the thorax 
during inspiration. The physical action of the respiration on 
blood flow towards and into the thoracic cavity will be discussed 
under the subject of intrathoracic pressure. (See Respiration.) 
Respiratory movements influence the blood flow in the large 
veins of the abdominal cavity by increasing the intra-abdominal 
pressure and in this way causing the blood contained in the vessels 
to be forced toward the thoracic cavity, where the intrathoracic 
pressure is at the same time decreased, due to the tendencj^ of 
the lung to draw away from the thoracic wall in inspiration. 

Conditions Causing Variations in Velocity and Blood 
Pressure. — As has been explained above, the rate and force of 
the heart beat are the most important factors concerned in the 
velocity of the flow of the blood and blood pressure. 2. The 
peripheral resistance, determined by the size of the small arteries 
due to their condition of tone, which is in turn determined by the 
action of their vasomotor nerve supply, also influences blood 
pressure and velocity. The mechanism of vasomotor regulation 
of the size of the small arteries has been discussed under the 
heading of "The Nerve Supply to Blood Vessels"; 3. The elas- 
ticity of the walls of the arteries has much to do with the regula- 
tion of the blood flow and the blood pressure as well as acting as 
a causative factor of blood flow, as has been discussed above; 
4. The quantity of blood in the vascular system is another factor 
in determining the pressure in the vessels. If the blood were 
evenly distributed throughout the vascular system the pressure 
would be equal, but this is never the case. The peripheral 
resistance offered by the capillaries and the force of the heart beat 
and the elasticity of the arteries constantly maintain a greater 



GENERAL AND OSTEOPATHIC. 93 

pressure in the arteries than exists in other parts of the vascular 
system. If, then, the peripheral resistance or the propelling 
force of the blood be varied it may be seen how the pressure and 
velocity may be varied accordingly; 5. The hydrostatic effect 
of the blood influences blood pressure and velocity to some extent 
according to certain physical laws, as follows: The downward 
pressure of a liquid column varies directly with the height and 
density of the fluid, but is independent of the cross section. From 
the first part of this law it will be seen that long columns of blood 
lying in a perpendicular plane for any great length of time would 
have the pressure materially increased at its lower end, which 
condition occurs in the long veins of the bodies of those who are 
on their feet for long periods of time. The excessive pressure 
thus caused often results in distension of the veins involved, 
causing varicosis; 6. Psychic conditions also influence blood 
pressure and velocity by causing variations of the vasomotors 
to the vessels and by affecting the rate and amplitude of the 
heart beat. 

Effects of Friction from Side Pressure. — The friction of 
the vessel walls, or side pressure, causes variation in the rate of 
blood flow by reducing the velocity of the blood. This resist- 
ance varies inversely with the size of the vessel, i. e., the pressure 
being increased in the smaller tubes and correspondingly reduced 
in large tubes. This factor affects the flow in the larger arteries 
very little, as the side pressure is only very slight. The aorta 
has a diameter (internal) of about 20 millimeters, the diameter 
of the arteries gradually decreasing in size down to the capillaries, 
which have a diameter of only about .009 millimeter. From 
this it will be seen that the side pressure is gradually increased 
as the blood reaches the periphery, being greatest in the small 
arteries and the capillaries. The increased resistance to the flow 
of the blood thus caused helps to maintain a greater pressure in 
the arteries than in any other part of the vascular system. After 
the blood has passed the capillaries and entered the larger veins 
the side-pressure influence is much reduced and the blood is more 



94 physiology: 

free to flow, but the force of the heart beat and the elasticity of 
the arteries is not active through the capillary resistance, and 
the velocity is therefore much diminished. 

Some Physical Laws Involved in Blood Pressure and 
Velocity. — The chief causes of the circulation of the blood have 
been given above with the conditions which influence it, causing 
variations in the velocity of blood flow and blood pressure, but 
there are certain physical laws involved, as follows: 1. The 
resistance of the movement of a fluid column varies inversely as 
the cross section of the tube through which it flows. This factor 
is of much importance in the study of vasomotor effects, as it 
explains how the pressure is increased with a general decrease in 
the velocity in conditions of vaso-constriction and how the 
opposite effects result from vaso-dilation; 2. The pressure in a 
moving fluid column varies directly with the resistance. This is 
another factor to be considered in the study of vasomotor effects, 
as a condition of vaso-constriction increases the resistance and 
this increases the pressure in the arteries. By this increased 
pressure in the arteries and the increased heart beat which follows, 
the systemic blood pressure will be increased. The influences of 
side pressure are also active in aiding to increase the pressure, as 
stated above; 3. The movement of a fluid column varies inversely 
with the cross-section of the tube through which it flows. The 
application of this statement can very readily be seen. It is 
active in influencing side pressure and in conditions of vaso- 
dilation and vaso-constriction; 4. The velocity of the movement 
of a fluid varies inversely with the resistance. It may seem at 
first that this is not true and that the pressure being equal, 
the blood will flow with a greater velocity through a smaller 
opening; but taking into account the entire column of blood 
and the above laws, it will be seen that the flow of the entire 
column is reduced and that the actual amount of blood 
supplied to a structure is decreased in proportion to the 
resistance; 5. Vascular pressure varies inversely with the 
elasticity of the vessel walls. It can readily be seen that if 
the contents of the ventricles of the heart were discharged into 



GENERAL AND OSTEOPATHIC. 95 

rigid instead of into elastic vessels the pressure would be 
much greater, as the same amount of blood would be contained 
in a less amount of space. When the ventricles of the heart dis- 
charge their blood into the arteries the extensibility of the arteries 
allows the walls of the arteries to distend and in this way more 
space is afforded to the blood. The arteries then slowly contract 
by virtue of their elasticity and: 6. The velocity and arterial 
pressure vary directly with the rate and amplitude of heart 
beat. This has been given above, but for the sake of completeness 
it should be given here. It has also been explained above how 
there may be an increased rate of heart beat without an increase 
in blood pressure, as an increase in heart rate is not always accom- 
panied by an increase in the force of the heart beat; but in most 
cases there is an increase in the force of heart beat with an increase 
in the rate, as these two functions seem to be influenced by the 
same kind of stimuli if not by way of the same nerve fibers; 7. 
Blood pressure varies directly with the quantity in the vascular 
system. This statement applies more especially to local areas 
of the body and is active in conditions of congestion. Any 
excess of blood in a part due to an interference with the drainage 
or increased resistance to the flow means increased pressure unless 
there is a compensating dilation of the vessels; 8. Pressure in 
fluid columns is equal in all directions. This law explains how 
the blood pressure is not influenced, except by gravity effects, 
by the direction of the artery or the course it takes. Another 
law that bears upon this same principle is, 9. That pressure in 
fluid columns is independent of the shape of the container. These 
two laws show how the branches of the large arteries have the 
same pressure and velocity (except for the increased side pres- 
sure) that exists in the artery of which they are branches; 10. 
The fact that fluids have elasticity of size or volume but not of 
form or shape is also to be considered in the above physical factors 
concerned in circulation. In cases of vaso-constriction, for 
example, in which the pressure is increased due to the increased 
peripheral resistance, according to Boyle's law (volume varies 






96 PHYSIOLOGY : 

inversely with the pressure) the blood is compressed but the 
amount of pressure in the different directions is not affected, and 
therefore vaso-constriction of a part influences equally the entire 
area so affected. 



j 




SECTION II 



RESPIRATION 



CHAPTER IX. 
GENERAL CONSIDERATIONS. 

Respiration includes all of those processes involved in the 
exchange of gaseous substances of the organism and its environ- 
ment. These changes consist essentially of the absorption of 
oxygen and the elimination of carbon dioxide. All living organ- 
isms, both animals and plants, require oxygen for their life 
processes, except a few bacteria — the anaerobic organisms, such 
as B. tetani and a few others. 

External and Internal Respiration. — By the term 
"external respiration' is meant the taking of oxygen into the 
lungs and the supplying of this oxygen to the blood of the 
capillaries of the alveoli and the elimination of carbon dioxide. 

" Internal respiration" is the term applied to the process of 
the exchange of oxygen and carbon dioxide between the systemic 
capillaries and the various tissue cells. 

Respiratory Organs. — In considering the relation of struct- 
ure to function in the study of the physiology of respiration, it 
becomes necessary for the student to make frequent references 
to texts on anatomy and histolog\ r . The following review work 
in these subjects is advised: A careful study of the structure of 
the air passages, viz., the nasal cavities, the pharynx, the trachea, 
the bronchi, the bronchioles, and the alveoli or air sacs. Certain 
points may be considered together with their functions, as 1. That 
the entire surfaces of the air passages are lined with ciliated 
epithelium, whose function is that of protection. It does this 
by carrying out the dust and other foreign particles that may 
enter with the air. (See structure and function of ciliated 
epithelium under contractile tissues) ; 2. The structure of the 
bronchial tubes and trachea is such that they are not compressible, 

99 



100 PHYSIOLOGY I 

and are therefore always open for the free passage of air; 3. The 
smaller bronchi are both cartilaginous and muscular. This 
insures that these tubes will remain open, and it is probable that 
the musculature is regulated reflexly in such a way as to regulate 
the supply of air to the air sacs; 4. The smallest bronchioles 
terminate in membranous sacs, the walls of which contain the 
arteries and capillaries of the pulmonary system, and it is in this 
way that the blood is brought almost directly in contact with 
the air in the alveoli. By this mechanism every red corpuscle 
comes in almost direct contact with the air, and in this way has 
its contained hemoglobin thoroughly saturated with oxygen. 

The Pleura. — The lungs, and in fact each lung, is covered 
by a double layer of membrane, the pleura. The inner or 
visceral layer covers the lung, and the parietal or outer layer is 
reflected about the thoracic cavity in such a way that the blind 
space — the "pleural cavity" — is left between. This is not a 
space, as the two layers of the pleura always normally lie in 
immediate contact, with a trace of lymph, the pleuritic fluid, 
between, to prevent friction during movements of respiration. 
It may be that under abnormal (pathological) conditions, such 
as the accumulation of air in this cavity (pneumothorax), 
caused by puncture, or the growth of gas-producing bacteria, 
etc., permanent separation of the walls may occur. Again, it 
may be that infection results in the production of pus, in which 
condition there may be a collection of pus, or pyothorax, or if 
there be presence of pus and gas, it is termed pyo-pneumothorax, 
etc. In such cases recovery is usually followed by the formation 
of adhesions of the two layers, and the roughened surfaces give 
rise to the " friction rubs" heard by the ear or stethoscope after 
recovery from lung affections. 

The pleura dips in between the lungs from below and down 
from above, and completely separates each lung in the mid line. 
The spaces left between are known as the mediastinal spaces. 
These again are only potential spaces, as they contain such thoracic 
viscera as the heart, the aorta with its branches, the pulmonary 
artery, the pulmonary veins, the ascending and descending vena 



GENERAL AND OSTEOPATHIC. 101 

cava, the azygos veins, the thoracic duct, the oesophagus and 
trachea, with the lymph glands and the lymph vessels. 

The Thoracic Cavity. — This cavity is formed by the walls 
of the chest and the diaphragm, and constitutes an adjustable 
cage which is completely filled hy the lungs, the heart, and the 
contents of the mediastinal spaces. The air content of the lungs 
is constantly being forced out and renewed by the movements of 
the walls of this cavity. Inspiration is caused by the enlargement 
of the thoracic cavity, the lungs swelling (due to external air 
pressure by way of the nasal cavities, pharynx, and trachea) 
to fill the enlarged cavity. The normal position and size of the 
thorax may be considered as that which exists at the end of a 
normal expiration, which means that all of the muscles involved 
in the act of respiration are at rest. 

Movements and Rate of Respiration. — -Expiration is 
caused by a diminution in the thoracic cavity (depression of the 
ribs and elevation of the diaphragm), which forces a part of the 
contained air out of the lungs. Expiration normally follows 
inspiration without pause, but there is a normal pause after each 
expiration and before the next inspiration. The normal number 
of expirations in the adult varies from seventeen to twenty per 
minute. This number is subject to certain conditions of var- 
iation, such as age, time of day, amount of exercise, etc. In 
the new born the respirations vary from forty to fifty per minute ; 
in the child of five to ten years the rate varies from twenty-five 
to twenty per minute, and shows a continual decrease to about 
twenty or thirty, while in men the rate is about sixteen per minute. 
After this age is passed the rate often increases until it is about 
eighteen per minute at the age of fifty. 

Active and Passive Respiratory Movements. — Any 
movement of the thoracic walls which increases the size of the 
thoracic cavity beyond normal, thus causing inspiration, is known 
as an active inspiration. The converse of this, namely, any move- 
ment which decreases the size of the thoracic cavity, thus causing 
expiration, is an active expiration. Active or forced respiration 
is not the normal way in which the air is forced from the lungs in 



102 physiology: 

ordinary breathing, but occurs only in deep breathing. After 
an active or forced expiration the thoracic cavity will return to 
the normal position (which is the position after a normal expiration) 
without any voluntary muscular force. This is passive inspira- 
tion. After an active inspiration the thoracic walls again return 
to the normal position without the aid of the voluntary muscles, 
which act is a passive expiration. 

CAUSES OF RESPIRATORY MOVEMENTS. 

To understand the mechanism of the respiratory movements 
it seems best to describe two classes of movements, viz., the 
movements of the walls of the chest, ribs, sternum, etc., and the 
movements of the diaphragm. 

Thoracic Movements. — A careful examination of the tho- 
racic skeleton will show how the ribs are attached and how they 
extend downward anteriorly, and how, when the ribs are raised 
by the contraction of certain muscles, enlargement of the 
thoracic cavity, both laterally and antero-posteriorly, results from 
such movement. It is therefore evident that all muscles 
involved in the elevation of the ribs are inspiratory muscles, as 
they increase the size of the thoracic cavity. Since, as has been 
mentioned, the ribs project downward anteriorly, any movement 
which raises them increases the size of the cavity, and it is equally 
true that any movement which depresses the ribs decreases the 
size of the thoracic cavity. 

Another factor concerned in the movement of the ribs is 
the nature of the anterior and posterior attachments. Anteriorly 
the ribs are attached to the costal cartilages, and when the ribs 
are raised as in the act of active inspiration, the cartilages are 
placed in a condition of strain, due to both bending and tortion. 
They therefore are tending to be forced back to normal by the 
elasticity of these cartilages. Posteriorly the ribs are attached 
to the vertebrae at two points by means of facets. The axis 
of rotation effected by these attachments points not directly 
outward, but forward and downward, so that as the rib moves 



GENERAL AND OSTEOPATHIC. 103 

it rotates in a plane which is at right angles to this axis, and this 
will cause the rib to be moved outward as well as upward. 

When the force which has been effective in raising the ribs 
ceases (the muscle contractions) the walls of the chest are 
lowered by the elasticity of the costal cartilages and the weight 
of the thorax. 

Movements of the Diaphragm. — Since the diaphragm 
is attached to the lower ribs, the lumbar vertebrae, and the' ensi- 
form cartilage, and when at rest extends far up into the thoracic 
cavity, it will be seen that when contraction of its musculature 
occurs it will be drawn down, and in this way the vertical diameter 
of the thoracic cavity will be increased. The diaphragm 
consists of musculature attached to a central tendon, which is 
free with the exception of its attachment to the pericardium, 
which does not interfere with its free movements. In addition 
to the increased vertical diameter caused by the lowering of the 
central tendon, the peripheral part of the cavity is increased by 
lowering of the musculature of the diaphragm. This drawing 
down of the diaphragm causes a decrease in the intra-thoracic 
pressure, and the external air pressure forces the lungs down 
firmly against the diaphragm, thus increasing the content of air 
in the lungs. There is never at any time normally an actual 
space between the lungs and the diaphragm, or any other part of 
the thoracic cavity. It is not suction, but pressure — pressure 
from the external air — which keeps the lungs in close contact 
with the thoracic cavity. Another result of the lowering of the 
diaphragm is the effect upon the abdominal viscera. As the 
diaphragm lowers, the pressure is increased in the abdomen and 
the abdominal walls are forced outward. To prevent the lower 
ribs from being drawn in by the contraction of the diaphragm, 
which, if it occurred, would tend to decrease the size of the thorax, 
the serratus posticus and quadratus lumborum muscles contract. 

Innervation of the Diaphragm. — The muscles of the 
diaphragm are supplied with motor and sensory fibers by the 
phrenic nerves. These nerves arise from branches of the third, 
fourth, and fifth cervical segments, and pass downward on each 
side through the mediastinal spaces. 



104 PHYSIOLOGY : 

That the musculature of the diaphragm is supplied with 
motor fibers by way of the phrenic can be shown by sectioning one 
phrenic in the neck region, which causes the cessation of movement 
of the corresponding side of the diaphragm. To determine this, 
an incision is made in the median line of the animal just below the 
ensif orm cartilage, and two fingers placed in against the diaphragm. 
The one side may be felt to contract down against the finger, 
while the other (the sectioned side) does not. It has been further 
shown (Porter) that section of one lateral half of the cervical 
cord above the origin of the phrenics causes cessation of movements 
of the corresponding side of the diaphragm. This points to the 
existence of a center in the medulla which sends fibers down to 
the phrenic of that side. It was further shown (Porter) that 
after hemi-section of one side above the origin of the phrenics 
(say the right side) the muscles of that side have quit acting, and 
if the opposite (left) phrenic nerve be sectioned, the left side of 
the diaphragm quits contracting and the right side again begins 
to contract. There has been much discussion as to the central 
connection by means of which such a seeming paradox could be 
caused, but it has been quite well explained by the following 
work : The demonstration of sensory fibers in the ^phrenic by 
Deason, by other work done by Carlson, and finally by the work 
done on series No. 3 by Deason and Robb. (See Part II.) The 
diaphragm also receives nerve fibers from the lower intercostals, 
but the phrenic is its chief motor supply. 

Nerve Supply to Lung Tissues. — The lung receives its 
nerve supply chiefly from the vagus. Fibers supply the muscula- 
ture of the air tubes with motor and probably with trophic fibers. 
It has been shown that the vagus supplies both motor and inhibi- 
tory fibers to the bronchial musculature. They are known as 
broncho-constrictors and broncho-dilators. The constrictors 
cause a decrease in the lumina of the tubes when stimulated, 
and the dilators produce the opposite effect. These variations 
cause in the size of the tube corresponding variations to the 
resistance of the air supplied to the lungs. Sensory fibers from the 
alveoli and probably from other parts of the lung are also carried 



t. 




Plate X. — 1-10, Sympathetic chain; 2 and 5, pneumogastric nerve; 3, thoracic spinal 
nerve; 4, fibers (rami) connecting spinal nerves with sympathetics; 6, posterior pulmonary 
plexus; 7, pulmonary artery; 8, divided bronchial tubes entering lung tissue; 9, pulmonary vein. 

The bronchial tubes with their vessels are shown forming as they do the root of the lung, 
also the lung tissue of the left lung in its relation to the tubes and vessels. The nerve plexuses 
formed by the pneumogastric and sympathetic, which are distributed to these tubes, are shown 
in their relation to the spine. Note also the spinal nerves and their communication with the 
sympathetic chain. By referring to plates 2, 3, 4, 5, and 6, the connections of these fibers 
with the cord and other autonomic nerves may be seen. 



GENERAL AND OSTEOPATHIC. 105 

in the vagus. These sensory fibers conduct afferent impulses to 
the respiratory center or centers, and are probably stimulated 
normally and at regular intervals by the distension of the alveoli. 
It is generally considered that this rhythmical stimulation of the 
respiratory center causes reflexly the action of the respiratory 
muscles, which cause the normal and rhythmical respiratory 
movements. 

It must be remembered that while the vagus is viscero-motor 
to the lungs it really has nothing to do with the movements of 
the lungs in respiration except reflexly, as explained in the preceding 
paragraph. The contraction of the musculature of the air tubes 
as controlled by the vagus may have something to do with the 
amount of air supplied and the rate of resp' ration, but even this 
is questionable. The lungs act only passively in the movements 
of respiration. 

The Muscles of Respiration. — These muscles may be 
divided into two groups, viz., those which are effective in 
inspiratory movements and those which are effective in expiration. 
Various methods have been employed for the purpose of determin- 
ing whether or not muscles are* active in producing movements 
of respiration, and also for determining whether they are con- 
cerned with movements of inspiration or expiration: 1. If a 
muscle or group of muscles is so attached that its contraction 
will tend to raise the ribs or otherwise increase the thoracic cavity, 
it is commonly considered to be inspiratory in function; 2. If 
the anatomical attachment is such that the contraction will depress 
the ribs or otherwise decrease the size of the thoracic cavity, it 
is considered to be expiratory; 3. If by artificial stimulation by 
way of its nerve supply or by stimulating the muscle directly, it 
depresses or lifts the ribs, it is classed accordingly; 4. If the 
muscle (Martin's method) contracts simultaneously with the 
contractions of the diaphragm, it is classed as inspiratory, and if 
it is found to contract alternately with the diaphragm it is classed 
as expiratory. According to the results of these various methods, 
the following seems to be the classification most generally 
accepted: 



106 PHYSIOLOGY I 

Inspiratory Muscles. — 

1. Diaphragm increases the vertical diameter of chest. 

2. Elevators of the ribs increase the lateral and antero- 

posterior diameter of chest. 
Levator cost arum. 
External intercostals. 
Scaleni — anticus, medius, and posticus. 
Sterno-cleido-mastoid. 
Pectoralis minor. 
Serratus posticus superioris. 
Expiratory Muscles. — 

1. Those affecting the diaphragm indirectly, the " abdominal 
press " muscles, which increase the pressure in the abdominal 
cavity and tend to force the diaphragm upward. 

External oblique. 
Internal oblique. 
Transversalis. 
Rectus abdominis. 

2. Depressors of the ribs: 

Internal intercostals. 

Triangularis sterni. 

Intercostalis lumborum. 

Serratus posticus inferior. 

Quadratus lumborum. 
Other muscles than those given are active in normal breathing, 
and while they have little or nothing to do with taking air into or 
expelling it from the lungs, they should properly be classed as 
muscles of respiration. They are the accessory muscles of respira- 
tion. If one will observe the dog while under ether it will be 
seen that the nostrils dilate and contract and the glottis moves. 
These movements, then, are caused reflexly with the movements 
of the other muscles, and their activity is probably regulated from 
the respiratory center, as in case of the movements of the other 
muscles. The muscles that elevate the nares and those that 
regulate the size of the glottis, and possibly others, should be 
considered accessory respiratory muscles. 



GENERAL AND OSTEOPATHIC. 107 

NERVE SUPPLY TO THE MUSCLES OF RESPIRATION. 

The nerve supply to the musculature of the diaphragm will 
be found discussed elsewhere. 

The muscles of respiration receive their nerve supply chiefly 
from the cervical and thoracic spinal nerves. The muscles of 
the neck and shoulders receive their nerve supply from the spinal 
accessory and various nerves from the cervical and brachial 
plexuses. The nasal muscles receive their nerve supply from the 
facial nerve, while the muscles of the glottis receive fibers from the 
vagi. The thoracic muscles of respiration receive their nerve 
supply from the intercostal nerves. The abdominal muscles 
receive nerves from the intercostals and lumbar plexus. 

These muscles are all striated or voluntary and are therefore 
under the control of the will ; but, on the other hand, their power to 
function rhythmically without, or independent of, voluntary 
control shows a co-ordinated acitvity, which is explained by 
assuming that they are controlled through the action of a 
respiratory center. 

The muscles show a double co-ordination of movement, in 
that the inspiratory muscles act together and the expiratory 
muscles act together. This again can be accounted for by assum- 
ing that they are alternately stimulated from the center. 

Since these muscles of respiratiom are all voluntary with 
the exception of the diaphragm, they are controlled in such a way 
that there is no danger of cessation of respiration from failure 
of the activity of these muscles for a sufficient length of time to 
cause death from suffocation. 

Action of the Respiratory Center. — This is a bi-lateral 
motor center, each side or part having control of the respiratory 
musculature of the corresponding side of the body. These centers 
are located on either side of the mid line of the medulla at the 
level of the calamus scriptorius and beneath the floor. It has 
never been demonstrated that there is a specially differentiated 
group of cells to which this function could be attributed, but 
its functional existence has been demonstrated by mammalian 



108 PHYSIOLOGY : 

research work. By making sections through the medulla of 
the living animal and determining the point at which the functional 
activity is lost, the location of the center has now been rather 
accurately located. This center should really be considered as 
a respiratory center, since in ordinary breathing the inspiration 
only is active, the expiration being passive in nature. When 
the breathing is deep and the expirations are also active, the 
center may act automatically in causing these movements. Some 
authorities believe there is a separate center for expiration, but 
this has not been proven. 

The efferent fibers (medullary spinal) extending from these 
centers pass down the cord chiefly on the same side (a few are 
known to cross to the opposite side) and terminate about the 
motor cells of the anterior horn of gray matter, from which the 
fibers (spino-muscular) extend to the various muscles of respiration. 
Because of the decussation (crossing) of some of these fibers, one 
of these centers may have some control of the musculature of the 
opposite side as well as that of the same side. There is good 
experimental evidence to show that these centers act autonom- 
ically, very much as the motor centers to the heart; that is, they 
have the power of originating their own energy to send impulses. 
That these centers can be influenced reflexly is also known. By 
the stimulation of any sensory mixed nerve leading into the 
cord, such as the sciatic or phrenic, the respiration can be much 
increased. (See Series No. 3, Part II.) 

Secondary Respiratory Centers. — -There is some evidence 
of the existence of respiratory centers other than the one described 
above. These centers are supposed to exist in the cervical and 
upper dorsal segments of the cord, and it may be that the reflex 
stimulation of these motor centers by afferent fibers coming from 
the periphery, as well as those fibers coming from the primary 
center in the medulla, cause the action of the motor fibers from 
the cord to the muscles. This has not as yet been positively 
demonstrated. (See Series No. 3, Part II.) 

Some authorities would add other so-called accessory respira- 
tory centers which they hold are located in the brain. Stimulation 



GENERAL AND OSTEOPATHIC. 109 

of one part of the mid-brain is claimed by Martin and Brooker 
to cause an increase in respiration. Others have held that these 
centers regulate the rhythmical activity of the primary center. 

Reflex Effects on Respiration. — As stated above, the 
stimulation of any sensory or mixed nerve causes an increase 
in respiration, which is explained by assuming that this stimulus 
increases the activity of the respiratory centers. Various other 
stimuli, such as cold air or water applied to the skin surfaces, 
mental excitement, etc., also often produce similar effects. It 
has been shown that stimulation of certain parts of the brain 
cortex also has this effect, which is caused by the stimulus affecting 
the center. 

Regulation of the Respiratory Center. — Since the 
automatic and rhythmical activities of the center determine the 
amount of oxygen supplied to the blood and tissues by way of the 
lungs, it is only natural to suppose that the condition of these 
structures (blood and other tissues) should in some way, by the 
law of demand of function, regulate the activity of the center which 
is to perform this important function. It has been shown how 
the stretching of the walls of the alveoli initiates the afferent 
impulses which go by way of the vagi and thus excite the center 
to normal activity, but how are the changes in rate and amplitude 
to be caused which increase or decrease the actual amount of 
oxygen supplied according to the demand of the tissues? It has 
been shown that the composition of the blood and the quantity 
of oxygen and C0 2 determine the action of the center. If the 
blood becomes highly venous, which means a deficiency in oxygen 
and a corresponding excess of C0 2 , this causes an increased action 
of the center. The converse of this statement is also true, viz., 
that an excess of oxygen in the blood inhibits (or fails to stimulate) 
the center. The first condition — the excess of C0 2 in the blood 
and stimulation of the center — would cause an increase in respira- 
tion which would meet the demands of function and supply the 
blood with oxygen, while the opposite condition — the excess 
of oxygen — would depress the activity of the center and decrease 
the oxygen supply to the system. The arterial blood supplies 



110 physiology: 

the center, and the condition of excess of C0 2 here merely means 
a relative increase and not an actual increase, as one might think 
of venous blood in this sense. Much discussion has occurred as 
to the nature of these effects, i. e., whether the excess of C0 2 
actually stimulates and the excess of oxygen inhibits, or whether 
in some other way the result is obtained. There is nothing but 
theory on this point, and a wide field is offered for research work 
along this line. 

Tonic Activity of the Afferent Fibers. — It has been shown 
that if the vagi are sectioned the respirations are slower and 
deeper, and it is believed that these nerve trunks carry afferent 
fibers which stimulate the respiratory center and tend to regulate 
its rhythmical activity. This tonic activity is probably initiated 
in the afferent endings in the alveoli of the lungs by inspiration, 
maintains a certain amount of tone in the center, and furnishes 
not only the stimulus for the normal rate but also affects the. 
amplitude of the respiratory movements. 

Other afferent fibers from the various parts of the respiratory 
tract seem to have specific function, some being stimulatory and 
some inhibitory to the movements of respiration. The superior 
laryngeal and glosso-pharyngeal, which supply fibers to the 
mucous membrane of the pharynx and larynx, when stimulated 
produce an inhibitory influence on respiration. It is probable 
that the glosso-pharyngeal produces a specific effect by inhibiting 
respiration during the act of swallowing, and that the afferents 
from the nasal mucous membrane by way of the trigeminal also 
produce a similar inhibitory effect. In case of the so-called 
irrespirable gases, such as ammonia, etc., respiration is prevented 
and this reflex mechanism may be considered as a protective 
adaptation, protecting the mucous membrane of the respiratory 
tract from injury. 









CHAPTER X. 
MOVEMENTS OF RESPIRATION. 

Normal and Modified Respiratory Movements. — 

Respiratory movements may vary greatly in amplitude and rate 
under different conditions without being abnormal. The ordinary 
or quiet respiratory movements, those which occur while the body 
is at rest, are known as eupnea, while very difficult or fast and 
deep breathing is known as dyspnea. The term dyspnea, however, 
is usually not applied to the deep and fast normal breathing which 
follows muscular exercise, the term being reserved for labored 
or abnormal breathing. Some authors, however, prefer to class 
all respiratory movements other than quiet normal breathing 
as dyspnea and to class dyspneic breathing under different degrees, 
such as mild, medium, extreme, etc. It should be remembered 
that in eupnea the inspiratory movements only are active, while 
the expiratory movements are merely passive. 

Normal eupneic inspiration is caused by the lowering of the 
diaphragm and to some extent to the levator costarum and external 
intercostals. Normal eupneic expiration is caused by the chest 
walls returning to normal position without the action of muscles, 
and is dependent upon: 1. The elasticity of the lungs; 2. The 
elasticity of the costal cartilages; 3. The elasticity of the abdomi- 
nal wall; 4. The increased pressure of the abdominal cavity 
and the weight of the thorax. In dyspnea the various muscles 
of expiration become active, and the activity of the muscles of 
inspiration is increased. 

Since normal inspiration is caused chiefly by the contractions 
of the diaphragm and since normal expirations are passive, any- 
thing which interferes with normal expansion of the abdominal 
cavity interferes with normal respiration and the thoracic type of 
respiration takes its place. Ill 



112 physiology: 

Disphragmatic and Thoracic Respiration. — As has been 
mentioned before, the movements of the diaphragm are most 
effective in causing normal inspiratory movements, and this type 
of breathing is classed as diaphragmatic or abdominal respiration. 
If the respirations are deep the muscles of the thorax become 
active, and this type of breathing is known as thoracic or costal 
respiration. In the abdominal type the diaphragm contracts 
first, which causes the abdomen to protrude and the movements 
of the thorax to occur later. Just the opposite of this occurs in 
thoracic respiration, i. e., the thorax is observed to expand first, 
which movements are followed by movements of the diaphragm. 
In the human, abdominal movements of respiration are common 
to men and thoracic respiration is common to women. "It has 
been a question whether this difference is a genuine sexual dis- 
tinction or depends simply upon differences in dress. Hutchinson 
inclined to the view that it forms what we should call a secondary 
sexual characteristic, and that its physiological value for women 
lies in the fact that provision is thus made, as it were, against 
the period of pregnancy." (Howell.) Hutchison, from a series 
of tests on young girls who had never worn tight dress, observed 
that the thoracic type of respiration was natural. There is, 
however, evidence against this view, in that certain women who 
have never worn tight clothing breathe normally by means of 
abdominal respiration as men do, and this would seem to be the 
more logical conclusion. 

Measurement of Respiratory Movements. — For the 
purpose of studying the nature of respiratory movements in animals 
caused by various kinds of nerve stimulation, etc., a respiratory 
tambour is attached to the side arm of a T tube, and tracings 
are made from this which record the frequency and amplitude 
of the respiratory movements. (See the various series of mama- 
lian work in Part II.) 

The exact amount of chest and abdominal expansion may be 
measured upon man with a tape or by means of special instruments 
for the purpose. 



34 CER. VERT. ROTATED 



5CWLEHUS P05TICU5 MUSCLE 




VERTEBRAL AltTlfiY 

Zd CERVICAL NERVE 
-SCALENUS MED/US 

SCALENUS ANTICUS 
BRACHIAL PLEXUS 
ht RIB (UPWARD) 



THOR. BRANCH TO 

BRACHIAL PLEXUS 
ht THOR. HERVE 
Zd RIB (UPWARD) 



ht INTERC05TAL 
NERVE & VESSEL 



Zd THOR. VERT. 
ROTATED. 



Plate XI. — Showing cervical and upper dorsal region in which we find the greatest amount 
of contraction and irritation in bronchial affections. The upper dorsal is commonly known as 
the bronchial spinal nerve center, and specific corrective work done in that region alleviates 
bronchial affections. The intercostal nerves are shown coming from the spinal cord, and in 
their relation to the ribs. The first rib on the right side is shown drawn up by muscular con- 
traction, due in part to the third cervical vertebra being rotated as shown in dotted lines, 
which irritates the nerve supply indirectly to this muscle. And the second rib on the left side 
is also thrown upward, partially by a rotation of the second dorsal vertebra, to which this 
rib is attached. The scalenus posticus muscle is shown attached to its upper border, which 
aggravates the abnormal position of the rib. 



GENERAL AND OSTEOPATHIC. 



113 



Measurement of Respiratory Capacities. — This is done 
by means of the spirometer, which records the exact amount of 
air expired, and by the measurement of such volumes of air the 
various respiratory capacities can be determined. 

Measurement of Breathing Capacities as Determined 
by the Spirometer. — 

1. A normal expiration after a normal inspiration (tidal 
air), 500 c.c. 

2. Greatest possible expiration (forced expiration) following 

a normal expiration (reserve or supple- 
mental air), 1600 c. c. 

3. The greatest possible expiration 
after a normal inspiration (supplemental 
plus tidal air), 2100 c. c. 

4. Normal expiration after greatest 
possible inspiration (complemental plus 
tidal air), 2100 c.c. 

Compare supplemental and com- 
plemental air from above results and 
account for the variation. 

5. The greatest possible expiration 
after the greatest possible inspiration 
(vital capacity), 3700 c. c. 

6. Residual air, 1000 c. c. 

7. Minimal, 1000 c. c. 
From the results of the above, 

calculate the quantity of air breathed 
in twenty-four hours. (Pulmonary ven- 
tilation.) 

These figures vary of course with 
sex, age, and with the size of the indi- 
vidual, but they can be very greatly increased by proper methods 
of respiratory exercise. 

Methods of Producing Artificial Respiration. — A knowl- 
edge of such operations is often needed by physicians, as they 
may at any time be called in cases of drowning or suffocation from 




Fig. 16. — This figure shows a 
modern spirometer, which is used 
for studing respiratory capacities. 



114 physiology: 

gas, etc. The method which seems to be in most common use 
consists in placing the patient upon his back with something 
under the upper dorsal region to elevate it slightly, but this is 
not always used. One individual now draws the arms well back 
over the head, thus drawing the ribs outward and upward and 
expanding the chest. After this movement the arms are lowered 
to the normal position or forced slightly against the chest, while 
a second worker presses upon the chest and abdomen to force 
more air out of the lungs. In the United States navy usually 
three individuals are used, one on each arm and a third working 
over the thorax and abdomen. This is a modification of the 
Sylvester method. It is essential to make these artificial move- 
ments correspond in time to about the normal respiration rate, 
i. e., eighteen per minute. This work is continued for an hour 
or longer if there be any signs of recovery at the end of an hour. 
Recovery has resulted after as long as two hours of such work. 

In case of drowning it is necessary to first place the patient 
head downward and force as much water as possible from the 
lungs. Placing the patient face downward over some object such 
as a barrel, and forcing downward and forward, often accomplishes 
this. It is also necessary to fasten or hold the tongue in such 
a way that it is prevented from blocking the respiratory passage. 

Schaefer's method, as he describes it, " consists in laying the 
subject in the prone posture, preferably on the ground, with a 
thick folded garment underneath the chest and epigastrium. 
The operator puts himself athwart or at the side of the subject, 
facing his head, and places his hands on each side over the lower 
part of the back. He then throws the weight of his body forward 
to bear upon his own arms, and thus presses upon the thorax of 
the subject and forces air out of the lungs. This being effected, 
he gradually relaxes the pressure by bringing his own body up 
again to a more erect position, but without moving the hands. " 

Artificial respiration can be effected in animals by the applica- 
tion of pressure to the chest at regular intervals, or if the animal 
is being operated, a bellows may be connected to the trachea 
and air forced directly into the lungs at regular intervals, allowing 
the escape as often as the air is forced in. 



GENERAL AND OSTEOPATHIC. 115 

Causes of Breathing at Birth. — Since the foetus does 
not breathe in utero, one would be inclined to inquire into the 
causes of the initiation of the first respiratory movements. 
Several explanations have been offered, as follows: 1. That the 
stimulation of the cutaneous surfaces as the child reaches the 
cold air renexly stimulates the respiratory center to activity. 
This would hardly hold in those cases in which the child begins 
to breathe as soon as its nose or mouth is exposed; 2. That the 
increased venosity of the blood caused by tying the umbilical 
cord and thus shutting off the placental blood excites the center, 
but this would hardly hold in those cases in which the child begins 
to breathe before the cord is tied. It seems most logical to 
accept both or either of these explanations, as both causes are 
known to be effective. The stimulation of the skin surfaces by 
spanking or changing the new born child from warm to cold 
water is usually effective when the process of respiration fails 
to begin otherwise. 

INTRAPULMONIC AND INTRATHORACIC PRESSURE. 

It has already been explained that the force which at all 
times holds the lungs against the walls of the thoracic cavity 
is the air pressure from the outside acting through the nasal 
passages, pharynx, trachea, and bronchial tubes. This pressure 
is therefore, with slight exceptions, always equal to the pressure 
of the outside air. The space between the lungs and the thoracic 
wall and the spaces between the lungs — the mediastinal 
spaces — constitute the intrathoracic space in which the lungs 
are contained. As has been explained elsewhere, these are not 
real spaces, but are filled at every point by the various thoracic 
viscera. If the thoracic wall were held distended and the lungs 
were rendered inextensible, then the thoracic cavity would be 
actual rather than potential, as it is in the normal chest of living 
animals. This can readily be demonstrated in mammalian opera- 
tions by making a puncture through the thoracic wall of one side, 
leaving the other unaffected. The lung on the punctured side will 



116 physiology: 

suddenly collapse because of the sudden admission of air into the 
thoracic cavity of that side, which equalizes the pressure on both 
sides, and since these forces are equal, the elasticity of the lung 
tissue is enough to cause the contraction, drawing the lung away 
from the chest wall. 

The pressure within the lungs is known as intrapulmonic 
pressure, and is always equal to (with slight variations) the out- 
side air pressure. The pressure in the thoracic cavity — intra- 
thoracic pressure (outside of the lungs and inside of the thoracic 
walls) — is always, with slight exceptions, less than the intrapul- 
monic pressure. Intrathoracic pressure is equal to the intra- 
pulmonic pressure less the force exerted by the elasticity of the 
lung, which causes it to tend to draw away from the thoracic 
wall. 

Causes of Decreased Pressure in the Thorax. — The 
lungs are developed from outgrowths of a part of the foregut, 
which is a part of the common tube from which the entire 
alimentary canal and its glandular structures are formed. The 
lungs in their process of growth and development are formed 
in a compressed thoracic cavity, as the thorax in embryo and 
foetus is compressed by the anterior flexion of the head and chest 
and by the large size of the liver in proportion to the liver of 
the adult. This causes the lungs to be comparatively small in 
proportion to the space they have to fill, when after the birth of 
the child the thorax expands. The lungs therefore are too small 
to fill the thoracic cavity without tending to draw away, and 
this elastic force or tendency to draw away from the walls of 
the thorax is one cause of the decreased intrathoracic pressure. 
This negative pressure does not occur suddenly after birth, but 
gradually developes as the thoracic wall grows, and the thoracic 
cavity is thus increased. 

The negative pressure in the thoracic cavity is maintained 
by the power that blood and other body fluids have of rapidly 
absorbing air which may get into this cavity accidentally. It 
may be shown that, after one lung has been made to collapse by 
puncture of the diaphragm or the lateral thoracic wall, if this 






GENERAL AND OSTEOPATHIC. 117 

opening be tightly closed the collapsed lung will soon become 
extended and the negative pressure will be restored. 

Variations in Intrapulmonic Pressure. — Since, as 
explained in the above paragraphs, the lungs are always exposed 
to the external air pressure, the lungs except while being affected 
by movements of the chest walls, that is, while at rest, are held 
distended by a pressure of air which is exactly the same as that 
of the external air. This is at sea level equal to 14.7 pounds 
per square inch, or 1033.3 grams per square centimeter, and sus- 
tains a mercury column of 760 millimeters, and is known as a pres- 
sure of one atmosphere. The intrapulmonic pressure at the begin- 
ning and end of inspiration, while the lung is quiet, is therefore 
equal to one atmosphere or the external air pressure, whatever 
that may be. 

This pressure varies during the active movements of respira- 
tion, being increased during inspiration because the external 
air does not pass into the lungs fast enough to maintain the normal 
pressure while the thoracic cavity is expanding. The exact 
converse of this condition obtains during expiration for, as the 
chest wall sinks rapidly to normal, the intrapulmonic pressure 
is increased while the air is being forced from the lungs. The 
amount of variation in pressure during inspiration and expiration 
varies with the amplitude of the respiratory movements, these 
variations being greatest in the deep, quick respirations. These 
variations in intrapulmonic pressure are not great, being from 
six to ten millimeters of water pressure in ordinary breathing and 
from thirty to one hundred millimeters of mercury in forced breath- 
ing. (Donders.) Any pathological condition which decreases 
the lumina of the air passages, such as inflammation of the nasal 
cavities or in fact inflammation of any part of the respiratory 
tract, particularly the glottis and bronchial tubes, causes increased 
variations in the intrapulmonic pressure and renders respiration 
more difficult. 

In the modified movements of respiration, such as sneezing, 
coughing, etc., the intrapulmonic pressure is often very greatly 
varied. These excesses in variation as well as those caused by 



118 physiology: 

the constricted glottis and bronchial tubes, are sometimes sufficient 
to materially affect the action of the heart and circulation. 

Variations in Intrathoracic Pressure. — As stated above, 
the term intrathoracic pressure refers to the pressure within the 
thoracic cavity, i. e., the spaces between the two layers of the 
pleura, which includes the lateral and mediastinal spaces. The 
pressure in the thoracic cavity (the so-called negative pressure) 
is always less than the intrapulmonic pressure because of the 
elasticity of the lung tending to draw the lung away from the 
thoracic wall. " Intrathoracic pressure, in fact, may be defined 
as intrapulmonic pressure minus the elastic pull of the lungs." 
(Howell.) 

The average pressure in the thoracic cavity (intrathoracic 
pressure) during the time the lungs are at rest (at the end of expira- 
tion) has been estimated to be 4.5 millimeters of mercury less than 
the intrapulmonic pressure. At the end of inspiration while the 
thoracic walls are distended and the elastic force of the distended 
lungs is increased, tending to draw away from the chest walls, 
the intrathoracic pressure is decreased to as much as seven or 
eight millimeters of mercury less than the intrapulmonic pressure. 

The intrapulmonic pressure therefore varies inversely with 
the distension of the lungs, as the greater the lung distension the 
greater the elastic force which tends to pull them away from the 
thoracic wall. Intrathoracic pressure therefore decreases as the 
depth of inspiration is increased. 

Taking as an average of the intrathoracic pressure the average 
pressure in the thorax at the beginning and end of inspiration, 
it would be about six millimeters of mercury less than the intra- 
pulmonic. Considering the intrapulmonic pressure to be 760 
millimeters of mercury, the intrathoracic pressure would be 754 
millimeters of mercury. Considering the time of the respiration 
pause, during which the pressure is less (same as at the end of 
expiration), the average intrathoracic pressure would be less than 
754. 

Under abnormal conditions, such as forced breathing, dyspnea, 
coughing, sneezing, etc., the intrathoracic pressure varies more 



GENERAL AND OSTEOPATHIC. 119 

than under conditions of normal breathing. In deep inspirations 
the intrathoracic pressure may be decreased to twenty-five or 
thirty millimeters of mercury less than the intrapulmonic pressure. 
Variations in the intrathoracic pressure, like variations in 
the intrapulmonic pressure, occur during inspiration and expiration 
and vary in the same way. 

Effects of Respiratory Movements on the Circulation. — 

Since the intrathoracic pressure is less than the intrapulmonic 
pressure, and because the intrathoracic pressure varies with the 
respiratory movements, these conditions will affect the flow of 
the blood and lymph whose vessels lie within or extend to the 
thoracic cavity. The pressure in the thoracic cavity where the 
large veins enter the heart is several millimeters of mercury less 
than the pressure along the course of these veins, and this assists 
in the blood flow towards the heart. During the movements of 
respiration the variation in pressure exerts a so-called " suction- 
pump" action on the blood in the veins and also on the lymph, 
which tends to "draw" the blood into the thoracic cavity at 
intervals and causes the incoming respiratory pulsations of venous 
blood and lymph. During this period of aspiration caused by 
thoracic inspiration the diaphragm is drawn down and there is 
an increased pressure in the abdominal cavity, which, because 
of the increased pressure exerted upon the abdominal vena cava 
and vena azygos major, tends to force the blood upward into the 
thorax where the pressure in decreased. 

There is probably no direct effect exerted upon the arteries 
of the thoracic cavity, because of their thick walls and the high 
internal arterial pressure. 




Fig. 17. — This figure shows the result of normal respiration on blood pressure. The 
increased blood pressure as shown in this tracing occurring at regular intervals is a result of 
inspiration, the pressure on the vessels of the thoracic and abdominal viscera causing an increase 
in blood pressure. This is explained in another way by assuming that the vaso-constriction 
center is stimulated to activity rhvthmicallv. 



120 physiology: 

Effects of Respiration on Blood Pressure. — In mammalian 
experiments if the blood pressure and respiratory tracings 
be taken simultaneously, it may be seen that there is an increase 
in blood pressure occurring during inspiration and a decrease during 
expiration. Various explanations have been offered, but the 
most probable one seems to be that during inspiration there is a 
greater quantity of blood forced into the aorta, because of the 
increased pressure and the increased rate of heart beat which 
occur during inspiration. Another theory offered to explain 
these variations in blood pressure assumes that it may be due to 
a rhythmical action of the vaso-constrictor center acting simul- 
taneously with the respiratory center. It is supposed that the 
same cause which stimulates the respiratory center to activit}" 
(most likely the afferent impulses to that center) at the same 
time stimulates the vaso-constrictor center,, causing its activity. 



CHAPTER XI. 

CHEMICAL AND PHYSICAL CHANGES OF 
RESPIRATION. 

It has already been stated that the chief purpose of respiration 
is that of supplying the various body cells of the animal with 
oxygen and relieving them of their gaseous wastes. "Just as 
the circulation provides for the exchange of fluid materials between 
the blood and the tissues, so respiration provides for the exchange 
of gaseous materials between the environment and the blood, 
and between the blood and the tissues. " (Luciani.) It is stated 
that even the anaerobic bacteria utilize oxygen in their metabolic 
processes, so it is seen that all living organisms require some means 
of respiration. A great majority of living organisms use free 
oxygen, some of the simpler forms taking it directly through their 
cell walls, while others (the more highly differentiated forms of 
life) have specialized structures, such as the lungs and gills, by 
means of which they collect oxygen from the air and water. In 
these higher forms there are two distinct processes, internal and 
external respiration, as has been previously discussed. 

The Physics of Respiratory Changes. — The inspired air 
is warmed to body temperature or nearly so, and as this requires 
the using of a certain amount of body heat energy, body tem- 
perature is so much reduced at every expiration. The expired air 
is also known to be almost saturated with water vapor which is 
taken from the lungs. At each expiration, then, there is a certain 
reduction in the body moisture. This may be readily observed 
in cold weather, when as the air is exhaled it is quickly cooled and 
the water vapor can be plainly seen. This absorption of water 
vapor from the lungs is another means of reduction of the bod}^ 
temperature, and in some animals (the dog) respiration constitutes 

121 



122 



PHYSIOLOGY : 






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,.->V&>»,7M;,\ff,,W»W^^^^ .. 



di«>^n^>C>^^^ 



& J> A A /» *,' .1'. I 

; VvtvvvvV:VVVV.Uv-v ; 



^V^/^^^' 



V-VV 



/ te^H^y^L 



Fig. IS. — This tracing shows the rhythmical variations in blood pressure. It will be noted 
that when the respiration is discontinued the blood pressure remains normal, which shows that 
the respiratory movements either directly or reflexly influence the rhythmical variations of 
blood pressure. 



the chief method of reducing body temperature. This is purely 
a physical change, as the reduction of temperature comes as a 
result of the reduction of water to vapor and the absorption of 
heat energy. It is a well-known physical principle that when 
liquids are reduced to gases this change is accompanied by an 
absorption of heat energy, and in this case the heat energy taken 
comes from the lungs. Since the lungs are so thoroughly supplied 
with blood, the circulating blood is thus cooled and the tempera- 
ture of the entire system is thus indirectly reduced. The moisture 
given up to the inspired air also comes from the blood, so respiration 
is therefore a method of reducing the water content of the blood 
as well as reducing its temperature. 

The Chemistry of Respiratory Changes. — The essential 
constituents of the air with which we are concerned in the study 
of respiration are oxygen, 20.96; nitrogen, 79; carbon dioxide, 
.04, and a few other things such as water vapor, dust, etc., which 
are to be considered as accidental constitutents and occur in 



GENERAL AND OSTEOPATHIC. 123 

variable quantities. Howell gives the following relations of 

inspired and expired air: 

N O CO2 

Inspired 79 20.96 0.04 

Expired 79 ■ 16.02 4.38 



4.94 4.34 

It will be seen from these differences that during respiration 
the used air has gained in CO2 but has lost in oxygen. It may 
also be seen that the loss in oxygen is greater than the gain in C0 2 , 
which means that not all of the oxygen has been used in oxidizing 
the carbon to form C0 2 , but that some has been used in some 
other way. It is most likely that this excess of oxygen is used 
in oxidizing some of the hydrogen of the food stuffs, the result 
being the formation of water. Traces of other gases, such as 
methane, hydrogen, etc., are found in expired air, which get into 
the blood possibly from the fermentation changes occurring in 
the alimentary canal. 

Gaseous Changes in the Alveoli. — Since the air in the 
alveoli or air sacs comes into almost direct contact with the venous 
blood of the lung capillaries, it is here that the gaseous changes 
occur which relieve the venous blood of its excess of C0 2 and 
replenish it with oxygen. It is evident that the air in the alveoli 
will have a higher percentage of oxygen than the expired air, as 
much of the inspired and expired air never reaches the alveoli 
and therefore remains unchanged. 

Diffusion of C0 2 takes place from blood to alveolar air, and 
just the reverse for oxygen. The oxygen taken into the blood 
unites with the hemoglobin of the blood, forming oxyhemoglobin, 
in which form it is carried to the systemic capillaries. The venous 
blood of the alveolar capillaries becomes almost completely satu- 
rated with oxygen, containing about nineteen cubic centimeters of 
oxygen per one hundred cubic centimeters of blood. Practically 
all of the oxygen of the blood is carried in the red corpuscles by 
the hemoglobin, but a slight trace may be carried in the plasma. 
"Not quite the whole of the oxygen is in chemical combination 
with the hemoglobin; a small fraction of it (0.1 to 0.2 vols, per 



124 PHYSIOLOGY : 

cent) is normally held in solution in the plasma. This quantit}^ 
is, however, less, under normal conditions, than what can be 
absorbed by an equal volume of distilled water at the same temper- 
ature. It may vary according to the Henry-Dalton law, i. e., the 
volume of oxygen dissolved in the plasma is proportional to its 
tension." (Luciani.) It is assumed by the physical theory 
that the forces which cause the exchange of gases in the lungs are 
the same as those which cause the diffusion of gases generally, 
and that this change is effected according to the same laws that 
regulate diffusion under other conditions. It may be stated that 
in general, if two gases or two solutions of a gas under different 
pressures be separated by an animal membrane, parchment paper, 
or other permeable membrane, the gases will pass through the 
membrane in one or both directions until the pressure is equalized. 
The results of physiological research have rather definitely demon- 
strated that the exchange of the gases in the lungs is effected by 
this physical process. 

Gaseous Changes in Tissue Capillaries. — After leaving 
the lungs the blood loses very little or none of its oxygen until 
it reaches the various capillaries to which it is to be distributed. 
The blood therefore reaches the capillaries of the tissues almost 
thoroughly saturated with oxygen, containing about 19% by 
volume, i. e., in one hundred cubic centimeters of blood there 
would be nineteen cubic centimeters of oxygen. It has been shown 
that all or practically all of the oxygen lost during its circuit 
through the system is lost in the capillaries, for while the blood 
enters the capillaries with its 19% of oxygen, it leaves the capil- 
laries with only 12% of oxygen. It is most probable that the 
same physical changes occur, and the same physical causes are 
responsible for the separation of the oxygen from its unstable 
compound of oxyhemoglobin and the passing of this free oxygen 
through the thin wall of the capillary to the cell, that are responsi- 
ble for similar changes in the alveoli of the lungs. It seems reason- 
able that the passage of CO2 from the tissue spaces back to the 
blood is caused in the same way, i. e., by the laws that govern 
diffusion of gases through a membrane. In the tissue spaces 



GENERAL AND OSTEOPATHIC. 125 

lying just outside of the capillaries, if the cells have been active, 
i. e., if they have been undergoing metabolic changes, C0 2 and 
other cell wastes are produced, which increase the "C0 2 pressure" 
or tension in the intracellular spaces, and therefore there is a 
tendency for the C0 2 to pass from these spaces through the capil- 
lary wall to the blood. There is also, because the oxygen in the 
tissue cells has been used, a low "oxygen pressure" or tension on 
the tissue side, a tendency for the oxygen to pass from the blood 
through the capillary wall to the tissue cells. This difference 
in pressure results in the supply of oxygen to the various tissue 
cells which are in need of oxygen, as the arterial blood passes 
through the capillaries. 

Carbon Dioxide in the Blood. — The method by means of 
which C0 2 is carried in the blood differs very materially from that 
of oxygen. A small percentage of the C0 2 is carried in physical 
solution in the blood plasma, and some is also probably held phys- 
ically in the corpuscles, but the greatest amount of C0 2 is held in 
chemical union with certain alkaline metals in the form of salts, 
such as acid sodium carbonate (HNaC0 3 ), etc. It is supposed that 
these compounds disintegrate while the blood is passing through 
the capillaries of the lungs, and in this way the C0 2 is liberated. 
It has been suggested that there is some experimental evidence 
to justify the assumption that the C0 2 may be held in proteins 
of the blood very much in the same way as oxygen is held in the 
hemoglobin. 

In addition to the oxygen and C0 2 of the blood there is some 
nitrogen present, which is held in physical solution. - 

Effects of Breathing Impure Air. — Every one has expe- 
rienced the depressing effects such as drowsiness, mental and physi- 
cal depression, and sometimes headache, which follow the breath- 
ing of expired air in poorly ventilated rooms. One may remain 
in a closed room for a length of time without noticing any effects 
other than drowsiness and mental depression, or possibly not even 
this, but if he goes into the open air for a while and then returns 
to the room which has been left closed he will immediately detect 
the foul odor. It is not so noticeable if one stays constantly in 



126 physiology: 

the room while the air is becoming foul, because the olfactory 
sense organs become so fatigued that it is not possible to detect 
the odor. The cause is not so much due to the repeated breathing 
of the C0 2 which is in too great amounts, but to the lack of suffi- 
cient oxygen, the latter having been used up by the continued 
breathing. The expired air also contains an excess of water 
vapor, dust, etc., and such conditions may become bad enough 
to cause death. There are some reasonably good results from 
experimental evidence to show that expired air contains some 
organic toxic substance other than C0 2 , which will in time result 
in death of those animals which have been made to breathe it 
for long periods of time, but it has not as yet been shown what 
this substance is if it really exists. 

Carbon dioxide, when present in quantities of 4% or more, 
causes rapid breathing and some distress, and at 10% blueness 
of the skin, deep depression, headache, and other symptoms 
result. If the percentage of C0 2 be increased beyond this amount 
the symptoms of depression vary with the amount of increase. 

From the above it will be seen that while a small percentage 
of C0 2 may be present in the air of the living room without causing 
any marked symptoms, even this is not good, and since it is known 
that expired air even in small quantities is not conducive to the 
best physical and mental work, it is necessary to have all living 
rooms and sleeping apartments thoroughly ventilated at all times. 
A good rule to follow for ventilating living rooms and sleeping 
rooms is to endeavor to keep the air on the inside of the room as 
nearly the same as possible as that of the outside air, avoiding 
drafts and dust. To do this many plans of ventilation have been 
devised, many of which are impractical. The reader is referred 
to some text on sanitation and hygiene for these various methods. 
The average living or sleeping room can be well ventilated by 
placing a piece of heavy cardboard or roofing paper at the top 
and bottom of the window (if there are two or more windows in 
the room it can be placed at the top of one and the bottom of 
another) in such a way as to direct the incoming air upward, 
thus preventing the draft from striking into the lower part of the 






GENERAL AND OSTEOPATHIC. 127 

room. The lower opening will allow the air to pass out freely. 
The shield should be placed over a sufficiently large area of the 
window that the window may be opened at least a foot from top 
and bottom, as large openings will not cause such sharp drafts 
as smaller ones. If an indicator is needed suspend a feather 
near the upper opening, and so long as it is moving the room is 
being well ventilated . This is a simple but very practical method 
of ventilating living rooms and the sick rooms where special ar- 
rangements for ventilation are not provided for. 

Various methods have been devised for keeping the oxygen 
and C0 2 in their proper proportions, but these methods have 
never been thoroughly satisfactory. 



CHAPTER XII. 

ABNORMAL RESPIRATORY MOVEMENTS AND 

OTHER CONDITIONS AFFECTING 

RESPIRATION. 

The term eupnea is applied to normal respiration, caused 
by the automatic and rhythmical activity of the respiratory center. 
Dyspnea is any marked increase either in the rate or force of 
respiration. This term is also used to denote labored breathing, 
and may be caused by any of the causes given above which in- 
crease respiratory movements. Hypernea is a term applied to 
marked dyspneic respiration, usually referring to the beginning 
of dyspnea. Apnea means the total lack of respiration, but 
the term is often used synonymously with suffocation or asphyxia. 
The normal cause of decreased breathing is excessive respiration, 
which over-supplies the center with oxygen. 

Modified Movements of Respiration. — This term is 
applied to those movements caused by the action of the various 
respiratory muscles reflexly or semi-reflexly, not resulting in 
respiratory movements which are intended to supply oxygen to 
the blood. The acts of sneezing, coughing, laughing, sobbing, 
yawning, and possibly vomiting, should be included in this list. 
These movements are not in any way purposeful, so far as the 
normal functions of the lungs are concerned. They are for the 
most part reflex. 

Cheyne-Stokes Respiration. — This condition is a varia- 
tion from the normal respiration, which consists of augmentations 
of respiratory movements with intervals of partial or complete 
apnea between. The respirations begin after a pause of some 
twenty to forty seconds and gradually increase, and after from 
five to twenty such movements have occurred they gradually 
128 



GENERAL AND OSTEOPATHIC. 



129 



decrease and finally cease, and another period of rest follows. 
There is nothing regular or definite about either the period of 
respiration (the dyspneic phase) or the period of apnea. 

The causes of Cheyne-Stokes respiration are not understood, 
but it is supposed that by some means there is an abnormal or 
irregular supply of oxygen or C0 2 or both, to the respiratory 
center. 

Cheyne-Stokes respiration has been known to occur rather 
constantly in certain pathological conditions, such as fatty degen- 
eration of the heart, uremic poisoning, arterio-sclerosis, etc. In 
those cases of Cheyne-Stokes respiration in which there is an 
increased intra-cranial pressure there is an increase in blood pres- 
sure and pulse rate during the dyspneic phase, and the converse, 
i. e., a fall in blood pressure and pulse rate, occurs during the 
apneic phase. In those cases in which the Cheyne-Stokes respira- 
tion is not accompanied by an increase in intra-cranial pressure 
there is a decrease in blood pressure and pulse rate. 



f^YVYv-^N 



Fin. 19. — This figure shows a condition which resulted from an artificial bony lesion 
produced in the upper dorsal region. The tracing shows a condition comparable to Cheyne- 
Stokes respiration. 



Effects of Exercise on Respiratory Movements. — Every 
one knows that muscular exercise increases the respiration in 
both rate and amplitude, and that the increase varies with the 
exercise. It will be readily seen that this prompt response in the 
respiratory apparatus is in answer to a demand of function, for 
the muscular exercise has increased the tissue metabolism, and 
this by the rapid use of the tissues' supply of oxygen furnishes a 
need for its replacement. The wastes of tissue metabolism, 
principally C0 2 , must also be renewed and this, too, calls for 
increased respiration. 



130 physiology: 

The cause of this increased respiration seems to be due more 
to the stimulating effects of products of muscle metabolism, 
e. g., lactic acid, acid phosphates, etc., than to the excess of C0 2 . 
These products of muscle metabolism when discharged into the 
blood stream are supposed to stimulate the respiratory center, 
thus causing the increased activity. 

Effects of Variations in Oxygen and C0 2 . — An increase 
in the CO2 content of air to three per cent, as shown by Zuntz, 
is sufficient to cause hypernea, and a percentage of from eight to 
ten per cent causes marked dyspnea. After a percentage of ten 
or fifteen per cent is reached, increased concentration is followed 
by a depression of the respiratory movements, and death results 
at a concentration of from forty to fifty per cent. There are 
no convulsions, the animal dying as if given a lethal dose of some 
narcotic. 

It has never been shown by physiological research that the 
breathing of pure oxygen has any beneficial effects on the body 
oxidations. It is known that there is normally an excess of oxygen 
in normal air, i. e., there is more than is actually needed, and it 
seems that any increase above this amount is unnecessary. It 
is claimed by Bert that an excess of oxygen becomes toxic, and 
is therefore not only a disadvantage but dangerous. Homeo- 
thermous animals are killed by a pressure of pure oxygen amounting 
to three atmospheres. This oxygen pressure causes the blood 
to contain twenty-eight volumes of oxygen per one hundred cubic 
centimeters of blood, the excess of oxygen being held in solution 
in the serum and is not contained in the hemoglobin of the corpus- 
cles. 

Decreased percentages of oxygen cause no marked effects 
until the oxygen is decreased about one-half the normal amount 
present in air. If the oxygen content of the air is reduced to 
ten per cent or less, the hemoglobin no longer carries its normal 
amount of oxygen and the tissues receive a deficient oxygen supply, 
which condition is known as anoxemia. 

If the atmospheric pressure is reduced to 250 millimeters of 
mercury (Bert), convulsions and death result. At this pressure 



GENERAL AND OSTEOPATHIC. 131 

the air contains about seven per cent oxygen. In cases of asphyxia 
death results from the lack of oxygen instead of the increase 
of C0 2 . 

Effects of High Altitudes. — Symptoms of headache, nausea, 
vomiting, vertigo, and general muscular weakness result in those 
individuals who go abruptly from low to extremely high altitudes. 
It is stated that these effects commonly occur in those who ascend 
in balloons to a height of 3,000 meters (9,800 feet) or more. This 
condition is commonly known as mountain sickness and is said 
to occur in tourists who try to climb to high altitudes, but while 
undoubtedly some effects do occur in individuals who have weak 
constitutions when they go as high as 10,000 feet or more, the 
results of those altitudes are often very much overestimated. 
In my own studies into these effects, having had occasion to live at 
an altitude of nearly 8,000 feet for several years, I am thoroughly 
convinced that the results as commonly stated are highly fallacious. 
An individual whose system is weakened by some infectious or 
constitutional disease, or who is for any reason not physiologically 
normal, will quite naturally note his inability to do as much muscu- 
lar work after having gone from a very low to a comparatively 
high altitude, such as a change from 1,000 feet or lower to an 
altitude of 6,000 or 8,000 feet or more, but even in these cases 
I have never observed symptoms of headache, nausea, vomiting, 
etc., that could be attributed to the effects of the altitude until a 
height of 10,000 feet or more had been reached, and this commonly 
occurs in those individuals (if they are otherwise normal) who 
over-exert themselves and who try to go from very low to very 
high altitudes. Any normal individual can within a few months, 
or even a shorter time, become so acclimated that other than 
" shortness of breath," he will experience no evil effects from 
altitudes of from 10,000 to 15,000 feet. 

If extremely high altitudes are reached, as in those cases in 
which men have ascended to 7,000 or 8,000 meters or more, extreme 
muscular weakness and general depression occur at a height 
of 7,000 meters or more, which continues until the individual 
becomes unconscious at about 8,000 meters. Death has occurred 






132 PHYSIOLOGY : 

at this height, while some individuals have survived even greater 
altitudes. 

Much theorizing and experimenting have been done to deter- 
mine the causes of these symptoms, but as yet no definite results 
have been obtained. 

Effects of High Pressures. — The effects of high pressures 
have been studied in divers', submarine, and caisson work. 
If under such conditions the pressure is increased to from four to 
six atmospheres or more, evil (toxic) effects result as a conse- 
quence of the high oxygen pressure, and death is caused by a 
pressure of from fourteen to sixteen atmospheres. 

The symptoms from working under ordinary high pressures 
usually occur when the worker returns to the normal air pressure 
and not while working under the high pressure. The symptoms 
are muscular pain, congestion, dyspnea, and sometimes paralysis. 
It is stated that if the worker goes gradually from the high pres- 
sures to the normal air pressure these effects do not occur. It 
is believed that the evil effects are a result of the sudden liberation 
of the pressure on the gases of the blood, resulting in the formation 
of bubbles, which tend to prevent the flow through the capil- 
laries. 

The Respiratory Quotient. — The respiratory quotient 

C0 2 eliminated, 

may be defined as the amount of — ~ — , -, — ; — the result of 

2 absorbed 

which is always normally less than one. Ordinarily, in an individ- 
ual living on an average mixed diet, the respiratory quotient 
varies from 0.6 to 0.9. This difference is due to the fact that an 
excess of oxygen is used in oxidizing a certain amount of hydrogen, 
forming water. Under varying conditions, such as a strictly 
carbohydrate diet, the respiratory quotient may equal unity, 

C0 2 eliminated 

i. e., the ~~p: r - r~= 1. In this case it may be that the excess 
2 absorbed 

of oxygen in the carbohydrate is used in oxidizing the hydrogen, 

and sufficient oxygen thus remains to unite equally with the carbon, 

resulting in C0 2 . A diet of fat, on the other hand, reduces the 



GENERAL AND OSTEOPATHIC. 133 

respiratory quotient (about 0.7), because the percentage of oxygen 
present in the fat molecule is comparatively low and therefore a 
greater amount of oxygen is needed for its oxidation. 

The respiratory quotient for protein foods is higher than 
that for carbohydrates (about 0.8), but it is variable because the 
percentage composition of the protein molecule is not constant, 
and also because the proteins vary in their amount of oxidation. 
The respiratory quotient is not materially varied by muscular 
exercise, except when the muscular work is long continued. The 
respiratory quotient may in rare cases exceed unity if the pulmo- 
nary ventilation is markedly increased or if continuous deep breath- 
ing is practiced, as this furnishes a greater amount of oxygen 
in proportion to the C0 2 to the alveoli. An increase in the 
respiratory quotient during convalescence from infectious diseases 
may, and usually does, occur. This is due to the conversion of 
carbohydrate food rich in oxygen to fats which have a lower 
oxygen content, the excess of oxygen being set free to be used in 
sparing the normal amount of oxygen supplied by the lungs. 
The excess of fat is stored in the body. There is in such cases 
an excess of C0 2 in the expired air, which may come from the 
breaking down of the carbohydrate molecule as it is disintegrated 
and formed into fat, but this chemical process is not well under- 
stood. 



SECTION III 



DIGESTION AND ABSORPTION 
AND ENZYMES 



CHAPTER XIII. 

FOODS. 

The useful constituents of the materials commonly used for 
foods may be divided into five fundamental groups, viz., carbo- 
hydrates, proteins, fats, water, and inorganic salts. Some authori- 
ties choose to name a sixth group, the albuminoids, which belongs 
to the protein group, but varying from proteins in that they have 
a different nutritive value. 

By the term food stuffs or proximate principle of foods is 
meant those substances which in various ways are absolutely 
necessary for the maintenance of life. A food in the physiological 
meaning may be defined as any material which, when taken into 
the body, may by the process of metabolism be converted into 
heat or some other form of energy (carbohydrates and fats), or 
which furnishes material for the formation of living tissue (pro- 
teins) or body fluids (water and salts), and which is not in any 
way detrimental to any of the normal physiological processes. 

Composition and Function of Food Stuffs. — ■ Carbo- 
hydrates consist of carbon, hydrogen, and oxygen, the hydrogen 
and oxygen being in proportion to form water. Carbohydrates 
are found chiefly in the starchy vegetables — potatoes, beans, 
bread stuffs, milk, cereals, etc. Oxygen is required for the oxidiza- 
tion of their carbon, which action results in the formation of CO2. 
The hydrogen and oxygen set free in the reaction form water. 
Carbohydrates are the chief source of body energy. The changes 
undergone during their metabolism are mainly exothermic, which 
means that the reduction of the complex molecule to simpler 
and more stable compounds is accompanied by the production 
of heat energy. Body heat energy, muscle energy, etc., thus re- 
sult from carbohydrate metabolism. 

Proteins consist of carbon, hydrogen, oxygen, and nitrogen, 
and are found chiefly in lean meats, albumin of eggs, beans, peas, 

137 



138 PHYSIOLOGY I 

etc. Protein is the only foodstuff that can build tissue, and this 
is its main function. The exothermic changes from its metabolism 
furnish some energy. 

Fats consist of carbon, hydrogen and oxygen, and are found 
in the fatty foods such as meats, olive oil, nuts, and some oily 
vegetables. Fats take no part in tissue building or the formation 
of body fluids, but yield heat by oxidation for heat energy and 
work. 

Inorganic salts such as the chlorides, sulphates, carbonates, 
etc. of sodium, potassium, calcium, magnesium, iron, and some 
other metals function in maintaining the normal density of the 
various body fluids, blood, lymph, etc., in forming essential 
constituents of internal secretions, and in performing certain 
specific functions, such as iron in hemoglobin. 

Water is not a tissue builder or energy producer, but is 
absolutely necessary to diet. The chief functions of water are to 
aid in the regulation of body temperature, to aid in the metabolic 
functions of other foods by acting as a menstruum or solvent, and 
by forming the proper concentration of the body fluids. 

The following list, taken from Howell, shows some of the 
most common foods and their relative food values : 

Carbohydrates. 
In 100 parts. Water. Protein. Fat. Digestible. Cellulose. Ash. 

Meat 76.7 20.8 1.5 0.3 ... 1.3 

Eggs 73.7 12.6 12. 1.1 

Cow's milk 87.7 3.4 3.2 4.8 ... .7 

Humanmilk ...89.7 2. 3.1 5.0 ... .2 

Wheatbread 35.6 7.1 0.2 55.5 0.3 1.1 

Rice 13.1 7.0 0.9 77.4 0.6 1. 

Peas and beans 12-15 23-26 1 . 5-2 49-54 4.7 2-3 

Potatoes 75.5 2.0 9.2 20.6 0.7 1.0 

Cabbage 90. 2-3 0.5 4-6 1-2 1.3 

Fruit 84. 0.5 10. 4 0.5 

The vegetable foods, as may be seen by reference to the list, 
are comparatively high in their carbohydrate content, and the 
meats comparatively high in protein and fat. Yet many of the 
vegetables are also rich in protein, especially the leguminous 
foods such as beans and peas, but the protein of meats is generally 
more easily and completely digested than those of vegetables. 



GENERAL AND OSTEOPATHIC. 139 

This is largely because the cellulose capsule of the vegetable foods 
prevents the action of the digestive juices. A very thorough boiling 
of such foods renders digestion easier. 

ENZYMES. 

Substances which have the power of producing fermentation 
were formerly divided into two groups, the living or organized 
ferments, such as yeast cells, bacteria, etc., and the non-living 
or unorganized ferments, or enzymes, such as those produced 
by living cells of the animal organism; for example, ptyalin, pepsin, 
trypsin, and so on. There is now, however, good experimental 
evidence to show that this difference will not stand, as many of 
the so-called enzymes have properties similar to the living ferments. 

Most authorities now consider that enzymes act similarly 
to chemical catalytic agents, that is, that the enzyme merely 
hastens the action or chemical changes occurring between other 
substances without undergoing any change in itself. The general 
term ferment includes, then, all of these substances the chemical 
composition of which is undetermined, which effect such changes 
in the living body. They may be denned as those substances 
produced from living cells, which in the presence of other substances 
increase the chemical changes without furnishing any chemical 
energy to the reaction, without undergoing any change in them- 
selves, and which are specific in their action. 

General Properties of Enzymes. — 1. It is generally con- 
sidered that enzymes are formed from a forerunner or zymogen 
material, which is found in the granular substance of a secreting 
gland. This granular substance may be demonstrated in the 
gland after a period of rest, and it is generally considered that 
these granules result from certain physiological changes of the 
cell substance of the gland. It is known that in some cases the 
formation of these substances is regulated by the nerve supply 
of the gland, which nerve is termed the trophic or nutritive nerve 
to the structure. 



140 PHYSIOLOGY : 

2. Specific Activity. — All enzymes are very specific in their 
action, which means that they do only one kind of work. Ptyalin, 
for example, has no effect on proteins or fats but acts only on 
carbohydrates, and here it does only a certain part of the reduction, 
leaving the work to be finished by another enzyme, maltase. 
This specificity of action probably holds for all enzymes. 

3. Temperature Requirements. — The optimum tempera- 
ture of an enzyme, or that temperature at which it acts best, is 
from 37° to 40° C. or body temperature. Their action varies 
inversely with any marked increase or decrease from the optimum ; 
that is, if the temperature be increased beyond this point their 
activity is reduced and their action is completely destroyed at 
from 70° to 80° C. If the temperature be reduced their activity 
decreases, but they are not destroyed by freezing. 

4. Completeness of Action. — The action of an enzyme is 
complete ; that is, it will effect entire reduction if the end products 
(products of digestion) be removed as the action proceeds. The 
removal of the end products used in body economy is normally 
effected by absorption. 

5. Concentration. — The quantity of enzyme necessary for 
complete action seems to be very small. If the temperature 
and reaction be kept right and the end products removed, the 
slightest amount of an enzyme will effect the complete reduction 
of a large quantity of material. Dilution of the enzymes often 
hastens their reaction. It has been shown that if enzymes are 
highly diluted with normal salt solution and the above conditions 
kept right, digestion is oftentimes materially hastened. (Deason 
and Robb.) 

. 6. Reaction Requirements. — Some enzymes require a neu- 
tral or slightly alkaline medium (ptyalin) ; some require an acid 
medium (pepsin), and some may act in either an alkaline, neutral, 
or acid medium (pancreatic lipase). 

7. Solubility. — Enzyme substances, generally speaking, 
are soluble in water and glycerine and are precipitated by alcohol. 

8. Reversibility. — Under certain conditions, it seems that 
some enzymes (lipase) have the power of reproducing the original 
substance or substances from certain end products. The reconver- 






GENERAL AND OSTEOPATHIC. 



141 



sion of such substances into their original forms after having once 
been reduced is known as a reversible reaction. 

9. Activation. — It has been found that solution alone of 
the zymogen material is not always sufficient to render the con- 
tained enzyme active. There are other substances known as 
enzyme activators. Organic activators are known as kinases. 
Entero-kinase of the intestinal juice, which activates trypsin of 
pancreatic juice, is an example. There is another class of sub- 
stances which assists the activity of enzymes, the co-enzymes 
or co-ferments, an example of which is the influence of bile salts 
on lipase. (See digestion of fats.) 

CLASSIFICATION OF ENZYMES. 



in 
in 



Enzymes are commonly classified according to their functions 
the process of digestion, the most important of which are given 
the following table: 



Name of enzyme. 

Ptyalin, a salivary 

diastase. 
Amylase, a pancreatic 

diastase. 
Invertase. 

Maltase. 

Liver diastase. 
Muscle diastase. 
Lactase. 



Carbohydrate Reducers (Diastatic). 

Function. 
Reduces starch to sugars, 
maltose. 



Where produced. 

Salivary glands; prin- 
cipally the parotid. 



Pancreas. 

Intestines — principally 

duodenum. 
Salivary glands and 

pancreas. 
Liver. 

Active muscle. 

Intestines. 



Reduces starch to sugars. 

Reduces cane sugars to 
dextrose and'ilevulose. 

Reduces maltose to 
dextrose. 

Reduces glycogen to 
dextrose. 

Reduces glycogen to 
dextrose. 

Reduces lactose to dex- 
trose and galactose. 3 

Protein Reducers (Proteolytic). 

Stomach wall. Reduces proteins to pep- 

tones and proteoses. 

Pancreas. Reduces proteins and pro- 

tein products to sim- 
pler forms. 

Intestines. Reduces peptones to 

simpler products. 

Fat-Splitting Enzymes (Lypolytic). 
Lipase (Steapsin). Pancreas. Reduces neutral fats to 

fatty acids and gly- 
cerine. 



Pepsin. 
Trypsin. 



3. Erepsin. 



142 PHYSIOLOGY : 

There are a great many other enzymes, some of which will be 
discussed elsewhere, but the ones given above are the most 
important. 

MASTICATION. 

Mastication is the process by means of which food stuffs 
are ground between the teeth and thus reduced to a triturated 
mass suitable for swallowing and digestion. The movements 
of the mandible in mastication are always voluntary, while none 
of the movements of other viscera concerned in digestion are 
entirely voluntary. The mandible is so articulated that a great 
variety of movements is possible, such as the direct raising of the 
jaw against the superior maxillary by contraction of the masseters, 
internal pterygoids, and temporal muscles. Depression of the 
jaw is effected chiefly by the digastrics. Lateral movements of 
the jaw are effected by the external pterygoids acting singly, and 
extension of the jaw is caused by the combined action of both 
external pterygoids. Other movements are the result of com- 
bined actions of two or more of these muscles. The tongue, 
muscles of the cheeks — the buccinators — -and the lips also aid in 
keeping the food between the teeth. 

Deglutition. — The swallowing process is commonly divided 
into three stages : The passage of the bolus of food first through 
the mouth, which is a voluntary act; second, the passage of the 
bolus through the pharynx; and third, the passage of the bolus 
through the oesophagus to the stomach. The two latter stages 
are caused by reflex, and are for the most part entirely independent 
of the will. 

The first stage is begun by raising the tongue against the 
hard palate, which forces the bolus backward through the isthmus 
of the fauces. The food must be moist in order that this act may 
be properly carried out, as dry foods materially inhibit the action. 

The second stage, the passage through the pharynx, must 
be effected quickly, since the pharynx also furnishes a passage 
for the air to the trachea, and respiration must be inhibited during 
the act. The impetus given to the bolus by the contraction of 



GENERAL AND OSTEOPATHIC. 143 

the mylo-hyoid muscle in the floor of the mouth, and the con- 
tractions of the pharynx suddenly force it into the oesophagus. 

The opening into the nasal cavities is temporarily closed by 
the raising of the soft palate, after the bolus has passed into the 
pharynx. The mouth cavity is closed from the pharynx by the 
raised tongue against the roof of the mouth, and by the contrac- 
tion of the pillars of the fauces. The laryngeal opening is tempo- 
rarily closed by the constrictors of the glottis, approximation of 
the vocal cords, the elevation of the larynx, and lowering of the 
base of the tongue. It is questionable whether the epiglottis 
plays any important part in the operation. The time required 
for this stage is about one second. 

The third stage, the passage of the food through the oesopha- 
gus, is caused by peristalsis of the muscles of its walls, and consists 
of a wave of dilation in front and constriction behind the bolus 
of food, as in other movements of the alimentary canal. The 
time required for this act is about six seconds for solids and about 
one-tenth of a second for the passage of fluids. When the mass 
of food reaches the cardiac sphincter, its progress is here retarded 
and the bolus slowly passes through into the stomach, five to eight 
seconds being required for the passage through the lower end of 
the oesophagus and the cardiac sphincter. 

The nervous control of the act of swallowing is mainly reflex : 
Afferent fibers from the soft palate and fauces by way of the 
superior maxillary division of the fifth cranial, afferent fibers 
from the pharynx by way of the fifth, ninth, eleventh and 
twelfth cranial nerves to the " swallowing" muscles. There is 
supposed to be a deglutition center in the medulla through which 
these movements are regulated, but this has not been demon- 
strated. 

That the movement of progressive peristalsis in the oesophagus 
is largely caused by reflex has been shown by sectioning the oesoph- 
agus or cutting out a portion of it, in which case the movement 
proceeds to the lower segments after having been started above. 
It is explained by assuming that the afferent stimulation from one 
segment excites the center or centers, and in this way the wave 
is continued bv reflex. 



CHAPTER XIV. 

SALIVA AND SALIVARY DIGESTION. 

The Glands. — There are three pairs of glands, which in 
order of size and importance are the parotids, the submaxillaries, 
and sublinguals. The parotid or lateral glands weigh from twenty 
to thirty grams each. The duct of Stenson empties the secretion 
into the mouth opposite the second upper molar teeth, is about 
40 m. m. in length and 3 m. m. in diameter. Their nerve supply, 
like that of all other salivary glands, is derived both from the 
cranial and spinal autonomics. Their cranial nerve is the tympanic 
branch of the ninth cranial or nerve of Jacobson, whose chief 
functions to the gland are secretion and vaso-dilation. The 
spinal autonomic (sympathetic) nerve supply is derived from the 
cervical autonomics and goes to the gland by way of the arteries 
supplying it, which are the posterior auricular, temporal, and 
transverse cervical. 

The submaxillary glands weigh from seven to ten grams 
each, are located below the jaw in the anterior part of the sub- 
maxillary triangle, their ducts (Wharton's) are about 45 m. m. 
in length and empty their contents into the mouth on either side 
of the frenum of the tongue. 

The cranial nerve supply is derived from the seventh cranial 
and goes to the gland by way of the chorda tympani, and the 
spinal autonomics are derived from the cervical sympathetics 
and go to the gland by way of the arteries which supply it, viz., 
the facial, lingual, and sublingual. The sublingual glands weigh 
from three to four grams each, and are located beneath the mucous 
membranes of the floor of the mouth. There are from eight to 
twenty small ducts (ducts of Rivinus) and one large duct (Bartho- 
lin's) which open into the mouth cavity. The cranial nerve 
144 



GENERAL AND OSTEOPATHIC. 145 

supply is the chorda tympani from the facial, and the spinal 
autonomic supply is from the submaxillary ganglion by way of 
the arteries supplying the gland, viz., sublingual and submental 
arteries. 

The Functions of the Nerves to these glands may be 
demonstrated by direct stimulation of the peripheral end of each 
nerve leading to the gland. If the peripheral end of the cranial 
autonomic fibers to the gland be stimulated, the results are: 
A reddening of the gland, a decrease in blood pressure of its 
vessels, a decrease of the granular material stored up, and an 
increase in the pressure of the secreted fluid in the duct of the 
gland, showing that there has been an increased secretion which 
has not resulted as a process of filtration, as the blood pressure in 
the gland was decreased during the time of the excessive flow. 

If the peripheral end of the cervical autonomic fibers to the 
gland be stimulated, the converse of the above results may be 
observed, viz., the vessels of the glands are constricted, the blood 
pressure is increased, there is an increase in the formation of 
zymogen granules in the glandular substance, the secretion is 
diminished in amount but is increased in specific gravity, and it 
seems to be richer in protein content. These nerves may therefore 
be considered trophic in that they control the building up of 
zymogen material from glandular substances. The same func- 
tions hold for the spinal and cranial autonomics of all of the 
salivary glands. 

The most reasonable theory of salivary secretion is that 
during the resting stage the glands store up zymogen material 
from cell substance, which function is due to the spinal autonomic 
fibers, and the discharge of this material is caused by the activity 
of the cranial fibers. Since these fibers are also vaso-dilator to 
the glands, it can be seen that the excess of blood makes possible 
the increased amount of fluid necessary for solution of the granules, 
and this constitutes the two essentials of the secretions. If the 
chorda tympani nerve be cut in the living animal, the gland will 
begin to secrete after a few days and may continue for weeks. 



146 physiology: 

This is known as the paralytic secretion, but eventually the 
gland atrophies and secretion ceases. 

The secretion of these glands is controlled by reflex mechan- 
ism, the afferent impulses going principally by way of the ninth 
cranial and lingual nerves from the mouth and tongue. Stimuli 
by these pathways stimulate the secretory center of the medulla 
to activity, and efferent impulses are sent out to the glands by 
way of the chorda tympani and Jacobson's nerves. That the 
mechanism is a reflex may be shown by cutting the efferent nerve, 
thus preventing secretion when food is taken into the mouth. The 
so-called psychic secretion — the flow of saliva which results when 
an animal is shown food — is probably caused by afferent stimula- 
tion of the secretory center in the same way as the afferent nerves 
from the mouth and tongue excite the glands to activity. 

General Properties of Saliva. — This fluid is colorless, 
opalescent, translucent, has a specific gravity of about 1.004, 
is almost neutral or amphoteric in reaction, being alkaline to litmus 
and acid to phenolphthalein. Saliva contains about .5% organic 
solids and certain salts such as phosphates, cyanides, sulphates, 
chlorides and carbonates of sodium, potassium, calcium and 
lithium. It also contains from 40% to 60% of C0 2 , which is 
mostly in the form of carbonates. The most important constitu- 
ents are physiological contents, viz., the enzymes ptyalin and 
maltase, which are its starch reducers, and mucin, which serves 
as a lubricant of the mouth and oesophagus during swallowing. 
Other than these, there may be named some incidental constitu- 
ents of saliva, such as salivary corpuscles or broken-down leuco- 
cytes, epithelial scales, and bacteria, of the latter of which there are 
normally present from fifty to one hundred different species in | 
the human mouth. The amount of saliva secreted in twenty- 
four hours varies from 1000 to 1500 cubic centimeters. 

Variation in Secretion. — The parotid gland secretes a 
fluid rich in ptyalin and deficient in mucin, while the exact 
converse is true of the other glands. There is a marked variation 
in the enzyme content of saliva of different species of animals. 
The dog, for example, has no ptyalin in its saliva, but it is very 



GENERAL AND OSTEOPATHIC. 147 

rich in mucin. It has never been demonstrated that the enzyme 
content can be changed by varying the diet. A carbohydrate 
diet in man, for example, will not increase the quantity of ptyalin 
in his saliva. 

Functions of Saliva. — The chief function of saliva in the 
human is the digestive changes which result from the action of 
ptyalin or salivary diastase. It converts boiled starch to maltose 
and dextrin, the intermediate stages of the reduction being not 
fully known. Maltase reduces these products to the simpler 
sugars. This action begins in the mouth and continues in the 
stomach. (See " Digestion in the Stomach. ") Another important 
function of saliva is lubrication, which is chiefly due to the mucin. 
Still another function is that of solution of dry foods, making 
taste possible, and which also assists in the formation of a bolus 
of the food for swallowing. 

Conditions Necessary for Salivary Action. — Ptyalin 
acts best at a temperature of from 37° to 40° C. There is no 
action at 0° C, but the enzymes are not destroyed by freezing. 
They are destroyed by a temperature of from 60° to 80° C. Sali- 
vary enzymes act best in a neutral or slightly alkaline medium, 
and thorough cooking of the starches materially aids their reduc- 
tion. 

Osteopathic Considerations. — Dr. Burns has shown that 
lesions of the jaw cause marked variations in salivary secretion. 
See report of her findings in Part II. 



CHAPTER XV. 
GASTRIC SECRETION AND DIGESTION. 

Gastric secretion begins a few minutes after food is taken 
into the mouth. The food does not need to be taken into the 
stomach to cause secretion of gastric juice. The effect is produced 
by afferent stimulation to the secretory center in the medulla, 
and the efferent stimulation goes to the stomach by way of the 
vagi. 

Methods of Study. — The Pawlow fistula or second stomach 
is made by surgical operation on dogs, preparing a second stomach 
separated from the first by a layer of gastric mucosa and having 
an outlet in the abdominal wall. Secretion in this way can be 
collected from the second stomach free from food at any time during 
digestion. The oesophageal fistula is made by section of the lower 
end of the oesophagus and making an outlet so that food swallowed 
is not taken into the stomach, but passed to the outside. The 
animal, when fed a "sham meal, " in this way produces the secre- 
tion of gastric juice in the stomach by reflex mechanism, but the 
juice is not contaminated with food and may be collected for 
experimental purposes. 

Test Meal. — The individual or animal is given a certain 
quantity of food, usually consisting of one shredded-wheat biscuit, 
and a certain length of time after eating the contents of the stomach 
are taken by stomach tube. This is the most common method in 
use for the study of pathological secretions in the human. Beau- 
mont's method is so well known that it needs no lengthy discussion 
here. His classical experiments on Alexis St. Martin, who had 
from a gun-shot wound an open fistula in the stomach, offered an 
excellent opportunity for study. Carlson has recently been 
doing some work on a similar case. 

48 



E50PH PLEXUS 

6th THOR VERTEBRA ROTATED 
CARDIAC £ HD OFSTOMH 




-RIGHT PNEUMO. M 
-VERTEBRAL ARTERY 
-J UP. CERVICGAHG 
—SUP. LARYNG. M. 

CERV. NERVE 



MIDDLE CERV. GANG. 



INF CERV. GANG. 
■1ST. THOR GAHG. 



CARDIAC BRANCHES 



JYMPATH CHAIN 



LEFT PNEUMO N 



RIGHT PNEUMO. N 
AORTA 



GASTRIC PLEXUS 
4REA TJPLAirCH.fi 



"rL.ENO OF 
~ STOMACH 



'MAUifUHICH.tt 
DUODENUM 



SUP VENA CAVA 

SUP. ME SEN T PL EX US 
LUMBAR NERVE 



INNOMINATE 



FEMORAL VEIN 
FEMORAL ARTERY 
— ANT CRUR. N. 
GANG. OF IMPAR 



Plate XII. — Side view showing nerve supply to the stomach. Eighth thoracic vertebra 
is rotated, showing interference with splanchnic nerves. Note the communication existing 
between the spinal nerves and sympathetics. Pneumogastric nerves are also shown. 



GENERAL AND OSTEOPATHIC. 149 

SECRETORY NERVES OF THE STOMACH. 

The Vagi. — That these nerves are secretory to the stomach 
we have the following evidence: First, that if the vagal branches 
to the stomach be sectioned, there is no secretion from a "sham 
meal" or from showing the dog food. Second, stimulation of 
the peripheral end of the vagi produces gastric secretion after a 
latent period of from five to twenty minutes. There is also some 
experimental evidence to show that the splanchnics are secretory 
to the stomach, but they are not as important as the vagi. 

Secretagogues and Hormones Another Essential Cause 
of Gastric Secretion. — Secretagogues such as the soluble sub- 
stances of meats, meat extracts, soups, etc., directly excite the 
gastric glands to activity by acting as a stimulus to the local 
nerve plexuses exciting a peripheral reflex, or by causing the 
pyloric mucous membrane to produce a chemical substance, 
secretin, a gastric hormone, which the blood carries to the gastric 
glands, stimulating them to activity. There is good experimental 
evidence to bear out the theory. (Edkin's, Starling's Physiology, 
1912 ed.; Howell, 1911.) A hormone is a chemical substance 
produced in one structure, which, when absorbed into the blood 
stream, excites to activity some other structure. It is probable 
that the hormones of the stomach are produced as a result of 
the activity of the secretagogue acting on the pyloric mucous 
membrane. 

There are, then, two essential causes of secretion : The nervous 
mechanism initiates and is responsible for the greater part of 
the flow. Hunger and appetite are the normal sensations which 
stimulate the flow of gastric juice at the outset. The hormones 
continue the secretion after the " appetite juice," due to the 
mental or brain effects and the vagal effects, have ceased. 

Effects of Variation of Food on Gastric Secretion. — 
The first secretion of a meal, the " appetite juice," is unaffected 
by any variation in food. (Pawlow.) But the second, the hormone 
or chemical secretion, is much increased by meats. It has however, 
the greatest digestive power following a bread diet. Pawlow has 



150 physiology: 

suggested that this may result from variation in stimulus to the 
gastric mucosa. This theory is not generally accepted. Large 
quantities of oils diminish the secretion of gastric juice. 

Effect of Drugs on Stomach Secretion. — Gastric secre- 
tion is increased by acid and diminished by alkalies. The 
administration of alkalies also diminishes secretion of pancreatic 
juice and other alimentary secretions, which possibly explains 
the causes of certain secretory disturbances from drugs. 

Gastric Digestion. — The purpose of digestion is the prepa- 
ration of food stuffs for absorption. 

Starch Digestion. — Digestion of starches from the action 
of ptyalin in the saliva swallowed with the food continues for 
some time in the fundic end of the stomach. It is later inhibited 
by the action of the hydrochloric acid of the gastric juice. 

Protein Digestion. — Pepsin is formed in the chief cells of 
the gastric tubules. It may be formed from a zymogen (propep- 
sin) like ptyalin. Peptic zymogen is changed to pepsin by the 
action of hydrochloric acid. Native proteins by the action of 
pepsin are reduced to peptones, according to Kuhne, by several 
intermediate stages, such as acid albumin or syntonin, primary 
proteoses or protalbumoses, and secondary proteoses or duteroal- 
bumoses. For the mechanism by which these changes are effected 
the reader is referred to works on physiological chemistry. Pepsin 
acts only in an acid medium. Peptic digestion is therefore a 
result of the combined action of pepsin and hydrochloric acid. 

There are several conditions which influence the action of 
pepsin. It acts best at an optimum temperature of from 37° C. to 
40° C. Its action is destroyed at 80° C. like other enzymes, and 
reducing the temperature inhibits its action. The normal amount 
of hydrochloric acid in gastric juice is from .2% to .4%. Any 
marked variation from this decreases the activity of pepsin. 

Hydrochloric acid inverts cane sugar to glucose and fructose, 
reduces some proteins to a jelly-like mass, assists in precipitating 
caseinogen of milk, and probably hydrolyzes some of the dextrin 
and maltose resulting from the action of ptyalin on starch. 



GENERAL AND OSTEOPATHIC. 151 

Rennin, Rennet, or (Thymosin. — This enzyme is formed 
also in the chief cells and is present in them in the form of a zymo- 
gen or a prorennin. It, like pepsin, also acts in an acid medium. 
The milk upon which it acts is quickly reduced to a solid clot, 
which, like blood clot, soon contracts, pressing out its liquid por- 
tion, the whey. Human milk forms a more flocculent clot than 
cow's milk. The reaction requirements are proper temperature 
and an acid medium, the clotting time varying inversely with 
the amount of rennin present. Rennin is used commercially in 
cheese making. By the action of rennin casein is first reduced 
to paracasein; this by the action of calcium phosphate forms the 
clot, which is an insoluble calcium salt. The exact nature of 
the chemical changes is unknown. The curd so formed is digested 
by pepsin of the stomach and by the trypsin in the small intestine. 
This latter process is proteolytic, resulting in proteoses, etc. 

Lactic Acid. — Bacterial fermentation of carbohydrates 
in the stomach results in the formation of sugar and lactic acid, 
but this action does not continue, as it is stopped by the hydro- 
chloric acid of the gastric juice. During the early stages of di- 
gestion only, carbohydrates are digested by fermentation and by 
the action of salivary enzymes. 

Gastric Lipase secreted in the stomach reduces some of 
the finely divided fat as during the first stages of gastric digestion. 
This action is also assisted by the dilute hydrochloric acid. The 
process is hydrolytic, reducing fats to fatty acids, but the greatest 
amount of fat digestion occurs in the duodenum. (Starling, 1912.) 

Artificial gastric juice for experimental purposes may be 
prepared by adding glycerine to macerated stomach mucosa. 
This may be used for the study of the proteolytic effects of gastric 
juice in the laboratory. By allowing gastric juice to stand for 
a day in the ice chest the pepsin is precipitated, which may also 
be used experimentally in the same way as the extracts. The 
chemical nature of pepsin is unknown. 

Stomach Absorption. — There is comparatively little absorp- 
tion in the stomach — small amounts of water, salts, sugars, and 
dextrins, albuminoids, peptones and proteoses, and certain sub- 
stances in solution, such as some drugs and alcohol. 



i52 physiology: 

OSTEOPATHIC LESIONS AND GASTRIC DIGESTION. 

We have shown that upper dorsal lesions in dogs cause a 
variation in gastric secretion and digestion. Dr. McConnell 
has also found similar results. It has further been shown 
that pathological changes result from osteopathic lesions. By 
the term " pathological changes" is meant the perversion of 
normal structure which renders it impossible for the structure 
involved to perform its normal function. There is experimental 
evidence to bear out the statement that dorsal lesions produce 
pathological lesions in the stomach. 

Dr. McConnell has experimented on a great many animals 
in this way. First he determines that the animal is normal in 
every way and then produces artificial bony lesions, in this case 
in the dorsal region of the spine. The animal is carefully observed 
daily for from ten to thirty days and after this length of time it 
is killed and a thorough post-mortem examination made, including 
careful examination of the stomach walls. The tissues are placed 
in a fixing fluid and then made into sections. These sections are 
stained and examined under the microscope, and it has been 
determined from the examination of a great many animals that 
actual changes of degeneration occur in the walls of the stomach. 
In our own research work we have confirmed these findings. The 
explanation of this is that the osteopathic lesion interferes with 
the normal function of the structures which receive their innerva- 
tion from the segment of the spine involved by the spinal lesion. 
The structures are affected in one or another of several ways; 
nutrition (trophism) is cut off or reduced and the structure to 
some extent degenerates. It loses the power of performing its 
normal physiological functions and by virtue of its vaso-constrictor 
nerve supply, which is also interfered with, it has not the power 
of regulating the blood supply and venous drainage and in this 
way and by involvement of the secretory nerves the secretions are 
rendered abnormal. They are deficient in amount, deficient in 
enzyme content and these are the probable causes of the decreased 
digestive ability of the stomach resulting from bony lesions. It 




Plate XIII. — S, Stomach and its nerve supply from the pneumogastric (X). Note the 
close connection between this nerve and the nerves of the head, making it easy for stomach 
troubles to cause headaches. D, Duodenum; III, motor oculi; V, trifacial; VII, facial; IX, 
glosso-pharyngeal ; X, pneumogastric; Sym, sympathetic nerve chain running down the front 
of the spinal column and connecting with the spinal nerves as well as the pneumogastric and 
splanchnics (Spl.) to the bowels; C P, cardiac plexus of nerves going to the heart; S C, superior 
cervical ganglion of the sympathetic; Oph, ophthalmic division of trifacial; C, ciliary ganglion: 
M, Meckel's ganglion; O, otic ganglion; L, lingual nerve; I D, inferior dental; G O, great 
occipital nerve. 



i 



GENERAL AND OSTEOPATHIC. 153 

may be argued that since the vagi are the chief secretory nerves 
to the stomach, dorsal lesions would not be responsible for the 
perversion of gastric functions; but as has been given above, an 
important part of the stomach secretion is due to normal functions 
of the stomach walls producing internal secretions, which continue 
the secretion of gastric juice; and whether the splanchnics are 
secretory or not, they are certainly essential in that they have 
much to do with the regulation of the blood supply and nutrition 
to the walls of the stomach and its glands from which the secretion 
comes. 



CHAPTER XVI. 

SECRETION AND DIGESTION IN THE 
INTESTINES. 

General Statement. — Products of gastric digestion are 
received at intervals into the duodenum where they are further 
digested by the secretions of the pancreas, liver, and duodenum. 
The internal secretions of these structures are to be discussed 
later. 

The Pancreas produces three well-known enzymes which 
perform essential functions in intestinal digestion. They are 
amylopsin, a pancreatic diastase; an amylolytic enzyme, trypsin, 
a proteolytic enzyme, and steapsin or lipase, which is a lypolytic 
enzyme. This organ is a long glandular structure which empties 
its secretion through the pancreatic duct (duct of Wirsung) into 
the midportion of the duodenum in common with the bile duct. 

Methods of Study. — A permanent fistula of the pancreatic 
duct may be made by attaching a part of the wall of the duodenum 
containing the duct of Wirsung to the abdominal wall. Pure 
pancreatic fluid for experimental study can be collected in this 
way. 

Another method by means of which the secretion of the 
pancreas is studied experimentally consists in the injection of 
certain substances intravenously. Secretin, an extract of the 
wall of the duodenum, when injected into the blood stream causes 
an excessive flow of pancreatic juice. The injection of pilocarpin 
into the veins also causes a flow of pancreatic juice, but because 
this drug has an influence on other structures, the product 
obtained differs so much from normal pancreatic juice that the 
results are not dependable. 

Secretory Nerves. — That the vagus is secretory to the 
pancreas, may be shown by the stimulation of its peripheral end 

154 



CT-SPLAtiCHMK N. 
DIAPHRAGMATIC GANGLIOti 
STOMACH 
llth THOU. VERT ROTATED 

L.SLniLUHAR OAtlGLiOti 

5. SPLANCHNIC N. 
R. SEMILUNAR 6AN6 
SUPERIOR MESENTERIC CANO 
LAST THOR OANO. 
SMALLEST SPLANCHNIC M. 
— RENAL GANG 
RLNAL PLEXUS 



1st LUMBAR GANG. 

2d LUMBAR VERT. ROTATED 
SMALL INTESTINE 
AORTIC PLEX. 




INF. VENA CAVA 
LUMBAR NERVES 



INF. MESENTERIC PEEK. 
HYPOGASTRIC PLEX. 



COLON 



CT. SCIATIC N. 
FEMORAL ARTERY 



MID HEMORRHOIDAL PLEX. 
—ANT CRURAL N 
VESICAL PLEX. 



I late XIV. — Showing the lower part of the spine and pelvic region, with spinal and 
sympathetic nerves to the organs in the abdomen and pelvis. The pelvic organs have been 
omitted, but the sympathetic nerves are shown, which supply and control these organs. No- 
tice the two lesions at the 11th dorsal and 2nd lumbar, which might influence the functions 
pi the spinal nerves as they leave the spinal column, also the sympathetic chain throughout 
its ciose connection with the rami. 



I 



GENERAL AND OSTEOPATHIC. 155 

after a degeneration of the cardio-inhibitory fibers. (Pawlow.) 
The secretion of pancreatic juice by the vagus is probably regulated 
reflexly from a secretory center in the medulla similar to the 
secretory mechanism of the salivary and gastric glands. 

Any decrease in blood supply materially affects the function 
of the pancreas ; therefore any interference with the normal regu- 
larity of heart beat or blood pressure varies the secretion of this 
structure. 

The spinal autonomics or splanchnic nerves also play an 
important part in the secretory functions of the pancreas. (Paw- 
low.) It has been shown that zymogen granules are stored up 
in the gland during rest. This we may reasonably assume to be 
a trophic effect of these nerves very similar to the changes which 
are known to occur in the salivary glands. Microscopic and 
macroscopic changes have been noted during activity of the 
glands. The vagi probably cause the discharge of this zymogen 
material and the active flow of the secretion. 

Hormones (or pancreatic secretin) produced by the mucous 
membrane of the duodenum when stimulated by the acid gastric 
secretions, cause an excessive flow of pancreatic juice. (Bayliss 
and Starling.) This stimulation of flow seems to be caused at 
regular intervals as each new quantity of acid chyme is passed into 
the duodenum from the stomach. There are certain substances 
present in the secretions of the duodenum which seem to have 
the power of activating pancreatic juice. They are called by 
Pawlow " ferments of ferments." This explanation has been 
questioned but is generally accepted. Bayliss and Starling have 
shown that "the smallest quantity of enterokinase is sufficient to 
activate any amount of trypsinogen if sufficient time be allowed ' ' 
(Starling), which is evidence against the composite nature of tryp- 
sin from trypsinogen and certain secretions of the duodenum. 
There are many chemical substances such as lime salts, etc., which 
have the power of activating pancreatic juice, but the nature of 
such action is not at all understood. The secretion begins a few 
minutes after eating and continues two or three hours. There is 
probably no flow of pancreatic juice while the stomach and duo- 



156 physiology: 

denum are inactive. Like the secretion of gastric juice, we may 
conclude that pancreatic juice is produced by two common 
causes: First, the action of secretory nerves, the splanchnics 
acting trophically in the formation of zymogen granules (tryp- 
sinogen) and the vagi causing their discharge; second, the con- 
tinuation of the secretion by hormone action. 

Protein Digestion. — Pancreatic juice when collected in 
a pure state from the duct has no action on proteins. The tryp- 
sinogen or forerunner of the proteolytic enzyme is reduced to 
trypsin by the action of enterokinase, which is a constituent of 
succus entericus secreted in the walls of the duodenum. When 
trypsinogen is so activated by enterokinase it is changed into a 
very active proteolytic enzyme, trypsin, which effects a very 
thorough digestion of the proteins that have passed partly digested 
from the stomach. These protein bodies, the peptones, albumi- 
noses, etc., are further digested into amino-acid compounds and 
other end products. Trypsin acts best in a neutral or slightly 
alkaline medium. End products of tryptic digestion such as 
amino-acid compounds interfere with further digestion, but if 
these end products are removed, digestion continues. 

Milk when acted upon by pancreatic juice is coagulated, the 
clot being readily proteolyzed. This may be the result of trypsin 
or a separate rennin ferment of the pancreatic juice. 

Carbohydrates are reduced by an amylolytic enzyme of the 
pancreatic juice known as amylolase or amylopsin. It quickly 
reduces starch to erythrodextrin and maltose, which action is 
similar to that of ptyalin. This action of hydrolysis continues 
until dextrose and glucose are formed, and again, like the action 
of saliva, it is another enzyme — maltase — which effects this latter 
reduction to the monosaccharids. This enzyme has no invertase 
and therefore there is no action on milk sugar or cane sugar. 

Fat Digestion in the duodenum is effected by the combined 
action of bile and lipase of the pancreatic juice, which reduces the 
neutral fats to glycerine and fatty acids. The enzyme is active 
in slightly acid, neutral or alkaline media. Saponification results 
if the reaction is alkaline. The bile salts assist in breaking down 



CAECUH- 




R. PtiEUMO. N. 
L PNEUMO.N 



ESOPHAG. PLEX 
■J /MP. CHAIN 



AORTA 



COELIAC PLEX. 



■JEMIiUtlARGAtlt. 
i-W.MESiEri.PLLX. 



SURMESSEtl.ART 



■ltiF.ME5SEt1.PLEX. 
■INF.ME5SEH. ART. 



■INF. VENA CAVA 
DESCEND. COLON 



LUMBAR fit. 



■SIGMOID ART 
■SICtWlDFLEA. 



S/NP CHAIN 



Plate XV. — This cut shows the stomach and a portion of the intestines with their 
nerve and blood supply. The stomach is also shown in a prolapsed condition, as indicated 
by the dotted outline. The sympathetic chain and its connection with the pneumogastrics 
is shown in relation to the walls of the stomach. 



GENERAL AND OSTEOPATHIC. 157 

the emulsion of fats, thereby allowing the enzyme to be more 
effective and furnishing a better solvent for the enzyme. Bile 
acids also assist in dissolving the soaps and fatty acids. 

General Properties of Pancreatic Juice. — Pancreatic 
juice is a clear, opalescent fluid, alkaline in reaction from the 
alkaline carbonates; has a specific gravity of 1.007; contains about 
.5% protein. The amount of secretion is from 500 to 800 cubic 
centimeters daily. There is inconclusive experimental evidence 
to show that the quality of the secretion varies with the kind of 
food given, an excess of protein producing a juice richer in trypsin, 
and an excess of carbohydrate results in a juice which is richer in 
amylopsin. 

Secretions of the Intestine.^— The tubular glands known as 
the crypts of Lieberkuhn produce a secretion — succus entericus — 
which is alkaline in reaction, due to sodium carbonate. Its value 
as a digestive secretion is questionable. 

Substances which may be found in extracts made from the 
walls of the intestines contain the following enzymes: Erepsin, 
a proteolytic enzyme which causes a further hydrolysis of peptones, 
proteoses, and so on; invertase, which reduces disaccharids to 
monosaccharids; nuclease, which reduces nucleins and nucleic 
acids, and the secretins or hormones as given above. 

The greater part of the secretion of the intestines is produced 
in the upper part of the small intestine. The colon secretes an 
alkaline mucous fluid, but there are no known enzymes produced 
in the large gut. There is probably some digestion continued 
in the large intestine from the action of the enzymes produced 
higher in the canal. The causes which regulate secretion of the 
intestinal glands are not well understood. It is highly probable 
that both the vagi and splanchnic nerves have at least a regulating 
effect on these secretions, and that the presence of food, especially 
when it contains pancreatic juice, excites these glands to activity. 
The secretion of these glands, therefore, may be regulated, to 
some extent at least, by hormone action. 

There seems to be a substance, an anti-enzyme, produced in 
the stomach and intestines which inhibits the action of proteolytic 



158 physiology: 

enzymes at the end of the digestive process, and the walls of the 
viscera are thus protected from the activity of these enzymes. 
The neutral or slightly alkaline reaction of the blood also prevents 
this activity. 

The Liver. — Bile, the external secretion of the liver, is 
temporarily stored in the gall bladder, from which it is emptied 
into the duodenum during digestion through the common bile 
duct. The combined action of bile and pancreatic lipase on fats 
has already been given. Bile in some respects is also an excretion. 
As an excretion the coloring matter of the blood hemoglobin, 
is constantly being thrown off. The gall bladder serves the 
double function of receptacle of such excretions and retainer of 
the bile, which must be stored and discharged when needed for 
digestive processes. Certain changes occur in the bile while it 
is contained in the gall bladder. It is concentrated by the loss of 
water and gains some mucin and nucleo-albumin, which are 
formed from the lining cells of the gall bladder. 

Constituents and Properties of Bile. — (Hoppe-Seyler, 
from Starling's physiology.) Mucin, 1.29%; sodium taurocholate, 
0.87%; sodium glycocholate, 3.03%; soaps, 1.39%; cholesterin, 
0.35%); lecithin, 0.53%; fats, 0.73%. The most important of 
these constituents so far as digestion is concerned are the bile 
salts and bile acids. 

Secretory nerves to the liver have not been demonstrated. 
Stewart states: "Of the direct influence of nerves, either on 
the secretion of bile or on its expulsion, we have scarcely any 
knowledge, scarcely even any guess which is worth mentioning 
here." It is generally considered that the secretion of bile varies 
directly with the blood supply to the liver; and because the spinal 
autonomics are vaso-constrictors to this organ, stimulation to the 
peripheral end of the splanchnics or the central end of the sensory 
or fixed nerve leading into the cord should, and according to most 
authorities does, decrease the flow of bile. 

Methods of Study. — The Pawlow fistula is made by attach- 
ing a section of the duodenal wall containing the opening of the 
gall duct into the abdominal wall so that the fluid may be collected 



>EJJACPLEXi/S 

WM£SSEHAfiT8 PLEX 

SEMILUNAR GAM 

■SrtfPATH. CHAIN 
AORTA 



5MALL MTE5TIHE 

lumbar mum 




Plate XVI. — Showing the blood and nerve supply to sections of small intestine and colon. 
Note that the fibers of the splanchnic nerves are distributed with the blood vessels supplying 
the gut. Note, also, the connections with the lateral chain ganglia. 



!! 









1 



! 



; 



GENERAL AND OSTEOPATHIC. 159 

externally. The common bile duct may be cannulated through 
an opening in the abdominal wall and the fluid collected in this 
way, or a cannula may be placed into the duct leading from the 
liver in order that the fluid may be collected before it reaches the 
gall bladder. 

Secretion of Bile. — Like pancreatic juice, the secretion 
starts soon after eating and continues for from two to four hours, 
the amount of secretion varying from 700 to 800 cubic centimeters 
daily. The greatest flow occurs at the height of intestinal digestion, 
which is about three hours after eating. 

Causes of Secretion. — The secretion of bile by the liver is 
a continuous process, but the amount is increased during digestion. 
Starling holds that the secretion of bile is effected by a hoimone — 
secretin — probably in the same way that the pancreas is excited 
to activity. He states: a In one experiment, for instance, the 
injection into the veins of five cubic centimeters of a solution of 
secretin, prepared in this way, increased the secretion of bile by 
the liver from twenty-seven drops in fifteen minutes to fifty-four 
drops in fifteen minutes. The rate of secretion was therefore 
doubled." Scott and Wendorff, working in the laboratories of 
the American School of Osteopathy, have by osteopathic stimula- 
tion of the mid-dorsal region increased the rate of flow from forty- 
nine drops in fifteen minutes to seventy-five drops in fifteen 
minutes. 

Effect of Various Foods. — The greatest flow of bile results 
from meat diet, while a meal of carbohydrates causes little bile 
to be discharged. 

Cholagogues are those substances which have the power of 
exciting the liver to increased secretional activity. Numerous 
drugs have been tried, but the various observers differ very widely 
in their findings. Stewart states that: " The only real cholagogues 
at present positively known appear to be the salts of the bile 
acids, which, given by themselves or in the bile, cause not only 
an increase in the volume of biliary secretion, but also an increase 
in its solids." The liver then produces its own cholagogue, and 
since its secretion varies directly with the blood supply to the 



160 physiology: 

gland, we can readily see the value of maintaining a normal nerve 
supply, since secretory nerves to the liver have not been demon- 
strated. 

The gall bladder is a sacculated diverticulum of the gall ducts 
containing smooth muscle, the contraction of which causes a 
discharge of its contents. Its opening into the gall duct is guarded 
by a sphincter valve, which structuie also regulates the discharge 
of the contents of the bladder. The nerve supply of the gall 
bladder comes from the vagi and splanchnics, and both pathways 
probably contain motor and sensory fibers. The chief function 
of the splanchnic fibers seems to be constriction of the bladder 
and dilation of the duct, while the chief function of the vagal 
fibers is opposite to this. There is little definite information to 
be had on this subject. The discharge of the bile by constriction 
of the bladder and dilation of its sphincter is effected by the 
presence of acid chyme in the duodenum. A flow is caused by 
each discharge of chyme from the stomach into the duodenum. 
Whether the mechanism is a reflex by way of afferent and efferent 
fibers in the spinal autonomics, or whether the discharge is caused 
by a hormone or secretin, as in the case of pancreatic juice, 
has not been determined. Probably both factors play important 
parts in the regulation of its flow. 

Functions of the Liver. — Besides the functions which have 
been given, the liver has others : An important internal secretion 
which will be discussed later, and the removal from the system 
of certain waste products of metabolism, such as cholesterin, 
lecithin, bile pigments and bile acids. The bile acids are end 
products of liver-cell metabolism of proteins. The bile pigments 
and bile acids are probably reabsorbed to a certain extent, and 
are therefore not wholly excreted. 

Bile is slightly antiseptic and tends to prevent bacterial 
putrefaction. Another important function of the liver is the 
formation of glycogen. Glycogen or animal starch (C 6 H 10 O 5 ) n 
is reduced by ptyalin to maltose and dextrin, like other 
starches. The liver furnishes a storehouse for the digested 
starch, and from twelve to fourteen hours after a meal of 



TRACHEA. - 

CERVICAL NERVE 

9 SUBCLAVIAN. 

DELTOIDEUS- 





CAROTID ARTERY 

"STERNO-CLEIDOMASTOIDEUC. 
-OMOHYOIDEUS 



BRACHIAL RLEX'JS 
L SUBCLAV 




: PECTORALIS MINOR 



'ECTORALIS MAJOR 



TERNO-MEMBRANE 



vPONEUROSIS 




INTERCOSTAL MUSCLES. 



■ LATISSIMUS DORS, 



-LINEA ALBA. 



OSTAL EDGE 



S OBLIQUUS OBDOMINIS EXTERNUS 



-OBLIQUUS OBDOMINIS 1NTERNUS 



3LIQUIS EXTERNUS • 



: V. 



-OBLIQUUS ABDCM1NISEXTERNUS. 



T. OBLIQUE 

^ANSVERSALIS ■ 
ECTUS 



SCENDING COLON 

vIENTUM 

EiSENTERIC VESSELS. 

^ECUM 



EUM. 
■^PENDlX 



3UINAL RING 



ERMATIC CORD 




-OBLIGUIS ABDOMINIS INTERNU5 



CREMASTE t 



Plate XVII. — Abdominal muscles removed, showing topographical position of the as- 
cending colon, its blood supply, and its relation to the adjacent viscera. 



GENERAL AND OSTEOPATHIC. 161 

carbohydrates it may be found in the liver in great quan- 
tities. (10% to 12% of the total weight of the liver.) The 
quantity of glycogen in the liver varies materially with the nature 
of the diet used — from 1 1-2% to 12%. The greater part of the 
carbohydrate food stuffs reaches the liver in the form of dextrose 
and levulose, where they are converted by a process of dehydration 
into glycogen. Certain end products of protein foods are also 
converted into glycogen synthetically in the liver, and protein 
substances are to some extent glycogen formers. Whether fats 
may be converted into glycogen is yet a moot question, but 

I there is good experimental evidence to show that certain end 
products of fat digestion, glycerine for example, may be changed 
to glycogen, but, if at all, a very small percentage of glycogen is 
so formed from fats. 

The functions of glycogen formation are not fully understood. 

i The most probable purpose is the storage of carbohydrate mater- 
ials for future use. The liver furnishes in this way a reserve 
supply for the system between meals. Carbohydrate foods are 
absorbed from the intestine during digestion and are carried to the 
liver by way of the portal vein in the form of dextrose, levulose 

I and galactose, and the change to glycogen is effected by the liver 
cells where it is stored. Were it not so changed the sugar content 
of the blood would be materially increased, which condition does 
not occur in normal individuals. The normal sugar content of 
the blood being at all times from 0.1% to 0.2%, any increase in 
this amount is pathological (the condition being known as hyper- 
glycemia) and the excess is thrown off by the kidneys, causing 
glycosuria, or sugar in the urine, which is a common condition in 
diabetes mellitus, a disease resulting from an inability of the system 
to store and metabolize its carbohydrate material. The liver, 
however, is limited in its ability to form and store glycogen, and 
if carbohydrates are eaten in excess or a large quantity of sugar 
is ingested, a temporary or alimentary glycosuria results. 

After a time the glycogen of the liver is reconverted into 
dextrose. It is carried from the liver in the form of sugar and 
re-stored in resting muscle in the form of glycogen, where it fur- 



162 physiology: 

nishes the chief source of energy for muscle activity. Glycogen 
is also stored in leucocytes, in the placenta, in various tissues of 
the embryo, and in many other tissues. The glycogen content of 
muscle is rapidly reduced by muscular exercise, and as the muscle 
depends upon the liver for its reserve supply, the glycogen content 
of this organ is also reduced by muscular activity. Starvation 
also reduces the glycogen body content. 

Another function of the liver is that of urea formation, which 
is affected by the liver cells. The former theory of the production 
of urea in the kidneys is now generally abandoned. 

OSTEOPATHIC CONSIDERATIONS. 

It is not surprising that the many attempts made by workers 
in general physiology have so far failed to demonstrate the func- 
tions of the nerve supply to the liver as well as the influence of 
the nerves to many other secreting glands. The methods in 
common use by most mammalian experimenters are enough in 
themselves to defeat their purposes. The stimulation, for exam- 
ple, of nerve trunks by artificial methods is a very unsatisfactory 
procedure and can surely not always be relied upon as giving 
satisfactory results. As has been explained above, the stimulation 
of the peripheral end of the vagus does not always produce secre- 
tion in the stomach glands, and when it does the stimulus is followed 
first by a period of latency during which time there is no secretion. 
It is definitely known that the vagus is secretory to the stomach 
and that the taking of food into the mouth is quickly followed by 
secretion. Why, then, does the direct stimulation not cause 
secretion? It is probably because of the inefficient methods 
used, overstimulation or something of that nature. The same 
explanation probably holds good for the liver, pancreas, and 
other secretory glands, and the fact that secretory nerves to the 
liver have not been demonstrated is of no great significance. 

In our research work on the liver we have quite conclusively 
shown (see Series No. 17, Part II) that osteopathic stimulation 



GENERAL AND OSTEOPATHIC. 163 

applied to the seventh, eighth, and ninth thoracic region produces 
an increase in the secretion of bile from 25% to 100% and that 
this flow continues for some time. According to the theory of 
secretion of the liver being due to an increased blood supply and 
that only, stimulation of this region should cause a decrease of 
secretion according to the theory stated in general physiology, 
as the splanchnic fibers are supposed to be vaso-constrictors and 
would thus decrease the blood supply to that gland. The work 
on this series has been done so carefully that there seems to be no 
possible doubt of the result, and we must therefore attribute the 
excessive secretion following such stimulation to specific secretory 
nerves or to vaso-dilator effects. It seems reasonable to accept 
the theory of secretory or trophic nerves. 

The fact that workers in general physiology have failed to 
demonstrate secretory functions in these nerves is of no particular 
significance, as they have never used methods which would demon- 
strate the normal functions of these nerves. Direct stimulation 
•of the peripheral ends of these nerves, or artificial stimulation of 
the cord segments from which these fibers originate, are inade- 
quate for the determination of the normal functions originated 
normally by the cell centers and propagated to the structures 
supplied by uninterupted paths of conduction. Osteopathic 
treatment (it may properly be called stimulation), surely accom- 
plishes the results. These are not recognized by other experi- 
menters, and will never be discovered by other workers until 
they have developed entirely new methods of experimentation. 
The reader, therefore, need not be surprised that our results differ 
widely from those of other physiological experimenters. To 
summarize, then, we may say that from the results of our work 
we must conclude that the liver is a gland of secretion and excre- 
tion, that the spinal autonomic nerves which supply it are secre- 
tory and trophic as well as vaso-motor, and that the functions of 
this organ can be materially influenced by osteopathic treatment ; 
that if a bony or other structural lesion exists anywhere which 
offers obstruction to the normal passage of impulses by way of 
the nerves, or if such lesion interferes with the normal arterial 



164 PHYSIOLOGY : 

supply to the segments of the cord within which the cell bodies 
of these nerves lie, or if the venous or lymphatic drainage from 
these segments be obstructed, or if the pathways of the afferent 
impulses to these segments be interrupted, surely the . normal 
functions of this organ will be impaired. 

The liver produces its own cholagogues, which are sufficient 
for its own regulation of function. Given a normal nerve and 
blood supply, this organ will by the production of its own chola- 
gogues perform more nearly its normal functions than can be 
hoped for by artificial means. 

It is well known that the liver, pancreas, and duodenum bear 
certain essential functional relations to each other. The 
duodenum produces secretions which to some extent, at least, 
regulate the functional activity of the liver and pancreas. 
These three structures may well be termed the splanchnic triad, 
and since the stomach is also regulated by the secretions of the 
duodenum that organ may also be classed as a member of this 
functional unit. Physiologists are too prone to neglect the func- 
tions of these structures as a unit and ascribe too much independ- 
ence to each. It is highly essential that the student of osteopathy 
realize the close relationships existing between different structures 
and consider his therapeutic methods accordingly. If, for example, 
a vertebral lesion is found which may influence one of these struc- 
tures it would be very unscientific to treat that one lesion and 
neglect others which might be affecting the functions of another 
of this functional triad. 

Intestinal Absorption. — Absorption from the intestines 
occurs by way of two routes. It may be taken into the blood 
stream directly, being taken up by the capillaries of the villi, 
or it may be taken up by the lacteals of the villi and carried into 
the thoracic duct, which finally empties it into the blood stream. 

Absorption occurs rapidly, especially in the small intestine, 
where the greater amount of the end products of digestion are 
taken up, the fats going by way of the lymph vessels and the 
greater part of the other food products by way of the blood stream 
to the liver. Some foods are sufficiently digested to reach the 



POST SPINAL ART 
VERT. VESSELS, 



CERV. PLEXUS 



SCALENUS POSTICUS 
1st. INTER- NERVE 



MEDULLA OBLONGATA. 

VERT. ART. 

1st. CERV. NERVE 



2nd. CERV. NERVE. 



SCALENUS MEDIUS 



SCALENUS ANTICUS 



BRACHIAL PLEXUS 
1st THOR NERVE. 



INTERCOSTAL NERVE 
and VESSELS. 



SUP LOBE OF R. LUNG. 



NF. LOBE OF R LUNG, 




DIAPHRAGM. 

SUBCOSTAL NERVE 

LIVER 

R KIDNEY 



ASCENDING COLON 



LUMBAR VESSELS 



R INNOMINATE 



GLUTEAL VESSELS 



R EXT ILLIAC 



G SCIATIC. 
COMES 
ERVI ISCHIADICI 



ANT CRURAL NERVE 

-FEMORAL ART.. 

FEMORAL VEIN, 

FEMOR. 



Plate XVIII.— Innominate cut away, showing position of the ascending colon in its 
relation to the right kidney, liver, and lumbar tissues. 



GENERAL AND OSTEOPATHIC. 165 

ileo-coecal valve within two hours after ingestion, but from five 
to twenty hours is required for the entire meal to pass into the 
colon. 

The mechanism of absorption is not clearly understood. It 
is reasonable to suppose from the experimental evidence at hand 
that absorption occurs from physical causes such as osmosis, 
diffusion, etc., and by a more complicated process of the activities 
of the living cells. Carbohydrates are mostly absorbed in the 
form of monosaccharids. Dextrose requires no digestion, but is 
directly absorbed as eaten. Starches and other carbohydrates 
need to be reduced, as explained above. The mechanism of fat 
absorption is not well understood. It may be that the fatty 
acids and glycerine are absorbed by the epithelial cells, or that 
the leucocytes lying between the cells ingest the fat droplets and 
in this way pass it on to the lacteals. The importance of the bile 
and pancreatic lipase on the preparation of fats for absorption is 
well shown in animals with permanent fistulas of the ducts of the 
gall bladder and pancreas. Instead of being absorbed, the fats 
when fed to these animals are passed out undigested. 

Protein substances are absorbed principally by the blood 
stream, being taken up by the capillaries of the villi, but in case 
of an excess of protein in the diet, some may be absorbed by the 
lymphatics. The chemica) nature of the proteins in the blood 
stream or the method by means of which they are absorbed is 
not fully understood. The end products of protein digestion 
resulting from the action of the digestive enzymes of the 
stomach and intestines, the peptones and proteoses, are probably 
absorbed directly without further change. Undigested proteins 
are absorbed to some extent at least, in the small and large gut. 
The good results obtained from feeding per rectum and the fact 
that these substances are absorbed from ligated loops of the 
small intestine, conclusively prove this. The absorption of pro- 
tein is greatest for the animal foods such as meats, eggs, milk, 
etc. (97% to 99%), while the percentage of absorption of the 
vegetable proteins is much lower, probably not more than 70% 
or 80%. 



166 PHYSIOLOGY : 

The functions of the large intestine may be briefly summarized 
as follows : It does not produce digestive enzymes, but some diges- 
tion occurs from the action of the enzymes passed on from the 
stomach and small intestines. It secretes some mucous and 
absorbs a much greater quantity of water from its contents than 
is secreted by its walls, and thus reduces the intestinal contents 
to a more solid mass, which moves very slowly through the colon, 
and by constant absorption of water it is formed into feces, which 
differ in amount and composition according to the nature of the 
food taken and the completeness of digestion and absorption. 
When a meat diet is given, the quantity is smaller and darker 
in color than when a mixed diet is ingested. The quantity is 
greatest on a vegetable diet, especially when foods rich in cellulose 
are taken. The average individual living on a mixed diet excretes 
from 150 to 200 grams of feces daily. Feces consist of the un di- 
gestible substances in foods, such as ligaments, cellulose and 
undigested foods, some starches, proteins and fats, and excretions 
such as cholesterin, mucin, epithelial scales, pigments, salts, 
and products of bacterial fermentation. The odor is due to certain 
ehemical substances, such as phenol, skatol, and products of 
bacterial putrefaction, hydrogen sulphide, etc. 

Bacterial fermentation occurs under certain conditions in 
various segments of the alimentary canal. It has never been 
positively demonstrated that bacteria are absolutely necessary 
to normal digestion, but on the other hand certain bacteria per- 
form functions which are not at all harmful, and in some instances 
seem to play important parts in digestion, such as the lactic-acid 
producing bacteria, bacillus bulgaricus, etc. The function of 
bacterial fermentation in the stomach has been given. Certain 
kinds of bacteria are normally present in the small and large 
intestines. In the small intestines carbohydrate-fermenting 
bacteria seem to perform essential functions, and those that 
ferment proteins are also slightly effective, but their action is 
inhibited by the organic acids, such as acetic and lactic acids. 
Since the reaction in the large intestine is normally alkaline 
(Howell), the environment is favorable to bacterial fermentation, 



m 



GENERAL AND OSTEOPATHIC. 167 

which is an almost constant process. Putrefactive fermentation 
in the colon reduces proteins, carbohydrates and cellulose, forming 
various organic and inorganic end products, some of which have 
been named. That a certain amount of putrefactive fermenta- 
tion is normal in the colon cannot be questioned, but if for any 
reason this process is excessive, abnormal irritation of the intes- 
tinal mucosa results, causing diarrhea, or by the formation of 
toxins, may cause various systemic disorders from auto-intoxication. 
The function of B. bulgaricus of Metschnikoff will be found in 
works on bacteriology. Suffice it to say here that we believe 
MetschinkofPs theory of the great detriment of other bacteria in 
the colon is probably very much overestimated. 



CHAPTER XVII. 

MOVEMENTS OF THE STOMACH AND 
INTESTINES. 



The alimentary tube consists in general of essentially the 
same layers throughout. A mucous layer within, usually a serous 
or protective layer on the outside, and a muscular layer between 
the other two, which consists of two coats — circular and longitudi- 
nal fibers — with the exception of the stomach, where a third coat 
consisting of the oblique fibers, is found. 

The Stomach. — The stomach is an enlarged portion of the 
tube which is structurally modified for the performance of certain 
functions. As Dr. A. T. Still puts it, it is the "mortar box" for 
the retention and mixing of the foods for other workers. The 
stomach consists of certain modified parts, as follows: The 

fundus is the large cardiac 
end lying to the left of 
the oesophageal opening; 
the intermediate or pre- 
pyloric portion, which 
lies between the fundus 
'intermediate, or and the antrum or pyloric 

pre-puloric region, x ^ 

portion; the intermediate 
portion and antrum are 
separated by the trans- 
verse band, which con- 
sists of an excessive number of circular fibers and functionally is a 
modified sphincter, at which point the essential movements of 
peristalsis of the stomach begin. The fundus serves chiefly as 
a receptor for the food stuffs. The body or intermediate portion 
is the chief secreting part, producing the greater amount of hydro- 
168 




fvndus 



Fig. 20. — Showing the general outline of the stom- 
ach with its different parts. (After Retzius, taken from 
Howell.) 



! 



i 




E5QPHA0U5 
■Mf/JJMfR'J PL EX. 



AUER8ACH PL EX 



CARDIAC PORTION OF STOMACH 



Ht- CELIAC PLEXUS 

GASTRIC ARTERY 

^SPLENIC ARTERY 

HEPAT/C ARTERY 

.PYLORIC ARTERY 
OASTRO-DUOD 
PYLORIC END. 

HNF.MESTQAHG. 
L OtiO COA T 

GA5T-EPIP.-DEKT. 

GA5Z-£PIP-J/H. 

ABDOMlrtAL AORTA 

CIR. COAT 

DUODEMUM 
ME 155 HERS PLEX.5UB-MUC COAT 

MUC. MEMBRANE 

SYMP. CHAIN 

LUMBAR VERVES 



fh„ a LA J E XI X.-— This cut represents the stomach with the oesophagus emptying into it, and 
S *w°i enUm (fij ; St par J of , the sma11 in testine) leaving it. The different lavers are shown 
of the wafls mUSCU stomach may be explained, also the nerve and blood supply 



GENERAL AND OSTEOPATHIC. 



169 



chloric acid and gastric juice, and the antrum constitutes the chief 
motor part, in which by peristalsis the stomach contents are 
forced to and through the pylorus into the duodenum. 

The stomach wall consists of the following layers: The inner- 
most layer is the mucous, below which is the submucous, contain- 
ing the secreting glands; the muscular layers are next, consisting 

of three layers of fibers, the innermost and 
least distinct of which is the oblique layer; 
the circular or middle layer is continuous 
from the cardiac sphincter to the pyloric 
sphincter, and is of greatest functional im- 
portance in the antrum; the longitudinal 
or outermost layer is continuous from the 
oesophagus to the duodenum. As has been 
stated above, the fundus serves as a reser- 
voir for the food stuffs, and therefore its 
muscular activity is very limited. The solid 
food of a meal often lies in the fundus 
for several hours, during which time the 
active antrum is throwing off the digested 
portions from the mid-stomach. 

Methods of Study. — The famous ob- 
servations of Beaumont on St. Martin, who 
from a gunshot wound had a permanent 
opening in the stomach, yielded important 
data, but the reliable information that has 
since been added by Cannon, who has 
studied these movements of the stomach by 
means of the X-rays, is now recognized by 
all. By mixing food with bismuth subnitrate, a good medium 
may be formed for producing Roentgen-ray effect. Photographs 
of the animal's stomach while digesting food are made and 
the movements determined in this way. The stomach of an 




Fig. 21.* 



*Fig. 21. — This figure shows movements of the stomach as recorded by Dr. Cannon by 
means of his notable X-ray study. This series shows the progressive changes in the form 
of the stomach of a cat taken at various periods after a meal. The meal was given in this 
case at ten o'clock A. M. 



170 



PHYSIOLOGY : 



animal may also be observed directly by exposing the stomach 
through an incision in the median line of the abdomen and 
covering the viscera with warm normal salt solution to prevent 
shock from exposure to air. 

Results. — The movements of the stomach may be grouped 
into three classes, all of which are simply peristaltic in nature: 
First, peristaltic waves beginning at the transverse band and 
extending over the antrum to the pylorus. These movements 

increase in amplitude as diges- 
tion progresses, serving to tri- 
turate and mix the food with the 
secretions, and tend to force the 
contents through the pylorus. 
These movements usually begin 
a few minutes after food enters 
the stomach. Second, other 
waves of lesser amplitude begin 
at rather regular intervals (every 
twenty seconds) in the mid- 
portion of the stomach and 
move towards the pylorus. Third, occasionally slight peristaltic 
waves may be seen beginning at the fundus and extending 
towards the pylorus, but these waves are not so great in amplitude 
as the waves of the antrum. 

Movements of the Small Intestine.— The various coats 
of the intestine are the same as those of the stomach, except that 
the oblique muscular layer is lacking. The movements of the 
intestine consist of a simple peristalsis, a relaxation followed by 
a constriction, which movement in the form of a progressive wave 
moves from the pylorus to the ileo-csecal valve. This peristaltic 
wave — the dilation followed by constriction — is explained by 
Bayliss and Starling as being due to the intrinsic nerves, since 

*Fig. 22. — This figure shows Pawlow's method of preparing an artificial stomach for the 
collection of gastric juice free from food stustances. The lower part or small stomach has 
been prepared by surgically separating a portion of the stomach in such a way that the secre- 
tion of gastric juice may be continued, but the contents of this small stomach do not in any way 
come in relation with the contents of the stomach proper. The small stomach is connected 
to the abdominal wall in such a way that the pure gastric juice as secreted may be drawn off 
for the purposes of study. 




Fig. 22.* 



i 



GENERAL AND OSTEOPATHIC. 171 

section of the extrinsic nerves does not prevent the movement, 
but the painting of the gut with nicotine or cocaine, which stops 
the action of the intrinsic nerves, abolishes the wave. "They 
must therefore be ascribed to the local nervous system contained 
in Auerbach's plexus, which we can regard as a lowly organized 
nervous system with practically one reaction, viz., that formulated 
above as the 'law of the intestines'." (Starling.) According to 
this authority, anti-peristalsis — a peristalsis moving stomach- 
ward — never occurs under normal conditions in the small intestines. 
The function of normal peristalsis is to force intestinal contents 
slowly through the alimentary canal. 

There is another, the so-called pendular movement of the 
small intestine, which consists of a series of contractions locally. 
These are rhythmical and occur in those parts of the tube contain- 
ing the food material. The effect of these movements is the 
division of the intestinal content into small masses, that it may 
better be. mixed with the digestive juices. 

Peristaltic waves and segmental contractions do not occur 
at the same time; that is, one does not interfere with the other, 
but a peristaltic wave may from time to time move the mass of 
the intestinal contents farther along, where it is again stopped 
and redivided by the action of the segmental movements. 

Movements of the Colon. — -The movements of the large 
intestine are very similar to those in the small gut, except that 
the peristaltic waves are less frequent and there is therefore a 
slower progress of their contents. "The law of the- intestines," 
viz., the peristaltic wave of dilation and constriction, holds good 
in the colon as well as in the small intestines. (Starling.) Cannon 
holds that there is frequently and normally an anti-peristalsis 
occurring in the ascending and transverse colon, while in the 
descending colon the movement is always peristaltic toward the 
rectum. The views of these authorities are therefore conflicting. 
The function of such a reverse peristalsis would be the retention 
of intestinal contents for further digestion and absorption. The 
contents are known to move slowly through the colon, requiring 
about two hours to pass from the csecum to the hepatic flexure 






172 PHYSIOLOGY : 

and from four to five hours to pass from the caecum to the splenic 
flexure. 

Nerve Supply to the Colon. — Of the extrinsic fibers, the 
inhibitors to the colon, as in the case of the small intestine, come 
from the spinal autonomics (chiefly from the upper and mid- 
lumbar segments) . Those supplying the rectum pass by way of 
the hypogastric nerve. The motor fibers to the colon, except 
possibly the descending colon, are furnished by the vagus; the 
motor fibers of the descending colon and rectum originate from the 
sacral autonomics (second, third and fourth), and go by way of 
the nervi erigentes to the hypogastric plexus. 

OSTEOPATHIC LESIONS AND THEIR EFFECTS ON THE 
FUNCTIONS OF THE COLON. 

The chief effects of lesions on the functions of the alimentary 
canal in general are discussed elsewhere in this chapter. It has 
been demonstrated that osteopathic lesions, whether occurring 
incidentally or produced artificially, most positively do interfere 
with normal movements of the gut, and in some cases seem to 
result in anti-peristalsis from reflex stimulation. (See p. 171.) 
As has been stated above, anti-peristalsis is not normal to the 
small intestine, and only occurs under abnormal conditions, 
such as exposure, injury, etc., of the intestinal wall. Research 
workers in osteopathy have shown that bony lesions may be a 
cause of anti-peristalsis. (Robb and Deason.) 

A weight of from five to eight grams is sufficient to check 
the progress of the forward movement of peristalsis in the intes- 
tines, and often produces excessive contractions or reverse peri- 
stalsis. The variations in pressure, then, caused by visceral lesions, 
faulty positions, etc., are all very important in the stud} r of normal 
and abnormal conditions that influence normal intestinal move- 
ments. The reader is referred to a most excellent discussion of 
mechanical principles by R. K. Smith, from which I quote the 
following: "By the use of the sphygmomanometer with a bag in 
the rectum it is ascertained that the pressure in the organ with 






GENERAL AND OSTEOPATHIC. 173 

the patient in the erect posture is about 25 m. m. of mercury. If 
the patient is then placed in a horizontal position this pressure 
is reduced to 15 m. m. If he will assume the quadruped posture 
this pressure entirely disappears and is replaced by a negative 
pressure of minus 8 m. m. The lifting of a heavy weight will 
increase the pressure to 100 m. m. Straining at stool will put the 
mercury to about 70 m. m. A cough will elevate it to about 100. 
The same experiments performed in the stomach show a positive 
pressure of from 4 m. m. during expiration and 12 during inspira- 
tion. " The value of these facts in the treatment of constipation, 
etc., is plainly evident. The collection of excessive amounts 
of gas in any part of the gut naturally interferes with normal 
movement. The cause of the gas may be a visceral or vertebral 
lesion, as is explained elsewhere in this chapter. 

THE NERVE SUPPLY OF THE ALIMENTARY CANAL. 

The nerve supply may be divided into two general groups, 
the extrinsic and the intrinsic. The extrinsic nerves may be 
again divided into two groups, the cranial autonomics, of which 
the vagi are the most important, and the spinal autonomics, 
commonly known as the sympathetics or splanchnics, those fibers 
which come from the spinal cord by way of the lateral chain ganglia 
and the peripheral plexuses to the viscera. 

The vagi are the chief nerves of visceral motion to the entire 
alimentary canal from the upper part of the oesophagus to the 
descending colon. They develop early in embryonic life and 
seem to follow the growing gut, and therefore supply also all of 
the glandular and other structures which develop from the gut, 
viz., the lungs, pancreas, and liver. Other than visceral motion, 
the vagi supply secretory, sensory, and possibly some viscero- 
inhibitor and trophic functions to the above named structures. 
It is very likely that they also supply some vaso-dilator fibers 
to the stomach and intestines. 

The spinal autonomics supply the entire alimentary canal 
with viscero-inhibitor, sensory, some secretory and trophic fibers, 






174 physiology: 

and are vaso-constrictors to the vessels of the stomach and intes- 
tines. There is some reason to believe that they may also be 
viscero-motor to the intestines, but the inhibitory function surely 
predominates. The spinal autonomics appear later, ontogeneti- 
cally and phylogenetically, than the vagal autonomics. They 
come from the neural-crest cells and migrate to the viscera by way 
of the anterior spinal nerves. The viscero-motor cells of these 
fibers lie in the antero-lateral horn of the gray matter of the cord. 
The functions of these fibers on movements of the intestines are 
often influenced by psychical conditions and by stimulation of 
cortical areas. There is therefore probably a pathway in the cord 
connecting the higher brain centers with these cell bodies of the 
lateral horn, but this pathway from the cortex to the cell bodies 
has never been definitely located. 

The intrinsic nerves of the alimentary canal consist of the 
cells and interlacing network of fibers lying within the walls of 
these viscera. They probably originate from neural-crest cells 
of the hind-brain region which have migrated by way of the embry- 
onic vagal fibers during early embryonic life, and while the layers 
of the gut are being formed. They are, therefore, probably more 
closely associated with the vagal autonomics than with the sympa- 
thetics. They constitute the plexuses of Auerbach and Meissner, 
are largely independent of the effects of the extrinsic nerves and 
are closely associated with the normal peristaltic movements 
of the gut. It is a well-known fact that movements of the gut may 
be continued after section of the extrinsic fibers, and it is natural 
to suppose that these fibers are associated with such functions. 

There is another factor which deserves mention here, the 
so-called myogenic function of smooth muscle. It has been shown 
by Bayliss and Starling that after the application of certain drugs 
to the wall of the gut, such as cocaine and nicotine, which paralyze 
the intrinsic fibers, the gut may still be made to contract by direct 
stimulation to its musculature. It is supposed that this stimulus 
passes from cell to cell of the muscles and thus transmits the 
energy. This is known as the myogenic or automatic action of 
the intestine. 



i 



GENERAL AND OSTEOPATHIC. 175 

SPHINCTER VALVES OF THE ALIMENTARY CANAL. 

The sphincter valve consists of an augmentation of the 
circular fibers of the tube, of which it forms a part. For example, 
at the cardiac end of the stomach there is an increase in the number 
of circular fibers at that point, making it possible for a greater 
amount of constriction in the tube. The same thing is true of 
the pyloric end of the stomach and the outlet of the rectum. 
Strictly speaking, these are not valves in the sense that we ordina- 
rily speak of valves. They are valves in that they perform the 
function of valves. They are valves in the sense that they prevent 
the food from passing from one segment of the alimentary canal 
to another until the necessary amount of digestion has occurred 
in that part of the gut. 

These valves are three in number. The cardiac, the so- 
called cardiac sphincter, constitutes a part of the oesophagus 
and makes up the part of the oesophagus at the cardiac end of 
the stomach. The pyloric valve is the so-called gate-keeper, 
which lies between the duodenum and the pyloric end of the 
stomach. The other one is the sphincter ani, which retains the 
content of the rectum until conditions are right for its discharge. 

Regulation ol the Action of Sphincter Valves. — It is 
necessary that the student of osteopathy understand the method 
by means of which the action of these valves is regulated. There 
is a tendency for the sphincter valve to open when a peristaltic 
wave in the tube has moved up to it, like for example : The peris- 
taltic wave of swallowing in the oesophagus passes down that 
structure and when it gets to the cardiac sphincter the latter 
dilates and the contents pass into the stomach. The same occurs 
at the pyloric end of the stomach. When the peristaltic wave 
from the antrum passes to the pyloric end there is a tendency 
for the pylorus to open and allow the contents of the stomach 
to pass out. This does not always occur because it is the function 
of this sphincter valve to retain the contents until sufficient diges- 
tion has occurred in the stomach. The conditions involved in 
the regulation of the opening of the cardiac sphincter are not 



176 physiology: 

known. The conditions which determine whether or not the 
pyloric sphincter will open or remain closed are these : First, that 
which is called the acid-regulating mechanism of the pylorus, 
which means that the pyloric sphincter will not open until the 
contents on the stomach side are acid in reaction. After this 
has been effected and the contents of the stomach have passed 
through the pyloric sphincter, they become alkaline in the duo- 
denum and the pyloric sphincter will not open again until the 
contents which have passed through by the stomach have been 
made alkaline by the duodenal secretions. We must have, then, 
two conditions — an acid reaction on the stomach side and an 
alkaline reaction on the duodenal side. The exact mechanism 
by means of which this acid or alkaline reaction effects the opening 
of the duodenum is not known. It may be that the regulation 
is a local nerve plexus at that point. Another condition necessary 
for the opening of the pyloric sphincter is that it tends to open at 
the time the peristaltic wave from the antrum of the stomach 
reaches it. If other conditions are right, the pylorus opens as 
the peristaltic wave reaches it. It is further regulated by a local 
nerve plexus. Not very much is known about the mechanism 
of this plexus. It may be a continuance of the Auerbach and 
Meissner plexuses. It is highly probable that the acid and alkaline 
reaction effects the regulation by its action on this local nerve 
plexus. The pylorus is also regulated, in part at least, by the 
extrinsic fibers which supply it. If the vagi be cut at a point 
just before they enter the stomach, the animal fed and then a 
post-mortem examination be made of the stomach some hours 
afterwards, it will be found that the contents of the stomach 
have not passed through the pylorus, showing that in some way 
the vagi have a regulating effect on the pyloric sphincter. There 
is also good reason to believe that the splanchnics also have a 
regulating effect on the pylorus. 

The function of the sphincter ani, as above mentioned, is 
that of retaining the content of the rectum until time is right 
for its expulsion, which is determined by the following conditions: 
First, the stimulation of the opening of the sphincter ani varies 




Plate XX. — Showing the circulation to and from the heart to the liver. The blood from 
the heart is given off to the stomach, spleen, intestines, etc., by branches (X, Y, Z, O), while 
the main artery continues and divides lower down to supply the lower extremities, and is 
picked up by the veins and returned to the heart through the inferior vena cava (7), while 
smaller veins return the blood from the stomach, spleen, intestines, etc., into and through the 
liver by way of the portal vein (3) before emptying through the inferior vena cava (7) into the 
heart. Thus there is a great amount of work thrown on the liver because during the digestive 
and assimilative processes a goodly proportion of the blood is drawn to these organs, and the 
liver must handle this extra quantity. A sluggish liver would necessarily impede the portal 
circulation and thus drive back the blood, which is supposed to be drained freely away from 
these organs during their activity. 1, Inferior vena cava; 2, aorta from heart; 3, 3, veins from 
liver (hepatic); 4, portal vein entering liver; 5, superior mesenteric vein; 6, right colic veins; 
7, inferior vena cava; 8, left colic vein; 9, sigmoid vein; 10, abdominal aorta from heart; 11, 
splenic vein; X, hepatic artery; Y, inferior mesenteric; Z, superior mesenteric; O, splenic artery. 



GENERAL AND OSTEOPATHIC. 177 

directly with the amount of material present. By this it is meant 
that the greater the amount of material in the rectum the greater 
the stimulation to the opening of the sphincter and discharge; 
second, the stimulation varies directly with the fluidity of the 
rectal contents ; third, the act of defecation is controlled and regu- 
lated by the nervous mechanism and is both voluntary and reflex. 
The act is partly under control of the will, but not wholly so. 

There is one other valve of the alimentary canal which should 
be considered and that is the ileo-csecal valve, which lies between 
the ileum and the caecum. Its function is to prevent the con- 
tents of the small gut from being passed into the caecum too soon. 
"The lowest two centimeters of the ileum present a distinct thick- 
ening of the circular muscular coat, forming the ileocolic sphincter. 
This sphincter relaxes in front of a peristaltic wave and so allows 
the passage of food into the colon." (Starling.) This sphincter 
is not controlled by the vagus, but is regulated by the splanchnic 
fibers. This valve differs from other sphincter valves in that 
it has in addition to the sphincter two folds which form prominent 
projections into the caecum. 

THE ALIMENTARY CANAL FROM AN OSTEOPATHIC 

STANDPOINT. 

The Stomach. — The normal movements of the stomach 
we have given as due to normal stimulation by way of the vagus, 
causing peristalsis, also normal inhibition effected by nerve im- 
pulses by way of the spinal autonomics. Viscero-inhibition in 
in this case means reduction of peristalsis. If for example in a 
normal animal the peripheral end of the vagus nerve be stimulated, 
there follows a peristaltic wave of the stomach, which goes through 
the latter and continues usually to the. pyloric orifice and down 
through the gut. If, after this peristaltic wave is well started, 
the splanchnics leading to this segment of the alimentary canal 
are stimulated, inhibition of the wave results. The same thing 
may be caused if stimulation is applied to any sensory or mixed 
nerve leading into the cord. The stimulation of some efferent 



178 physiology: 

or mixed nerve leading into the cord is equal in effect to the stimu- 
lation of the peripheral end of the spinal autonomics. It causes 
a condition of inhibition to the peristaltic movement in the aliment- 
ary canal. Stimulation of the vagus results in peristalsis, which 
is stopped by stimulation of the splanchnics. Now if a bony 
lesion is produced in the mid-dorsal or lower dorsal region and a 
peristalsis started by stimulation of the vagi, the stimulation of 
the central end of a sensory nerve does not inhibit peristalsis. 
Spinal lesions therefore interfere with normal functional activity 
of the nerves to the segment of the alimentary canal which they 
supply. 

The question is sometimes asked, why do not animals suffer 
from disease conditions as a result of osteopathic lesions as human 
individuals do? The answer is that they do. No. 33 of Series 4, 
a large dog, about two years old, in a perfectly healthy condition, 
had a voracious appetite, eating about four times as much as a 
normal dog, but lost in weight all the time. On examination it 
was found to have a marked lesion of the fourth dorsal. This 
animal continued to decrease in weight. When it was found 
that it would not normalize, it was fed a full meal and killed about 
three hours afterward. The stomach contents were found to be 
almost entirely undigested, the secretions were decreased in 
amount, and there was evidence of fermentation. 

The intestines are affected very much the same as the stomach 
by bony lesions of the spine. If the peripheral end of the vagus 
be stimulated a peristaltic wave is produced in the intestine which 
is inhibited by stimulation of the peripheral end of the splanchnics 
or the central end of some sensory or mixed nerve which leads 
into the cord; that is, the movement of the gut is either reduced 
or completely inhibited. If the animal is then lesioned in the 
mid-dorsal region and the experiment repeated the vagus causes 
peristalsis of the gut, but stimulation of the central end of a sensory 
or mixed nerve coming into the cord does not cause inhibition of 
the peristaltic wave. This means that in some way the lesion 
has prevented the normal function of the spinal autonomics from 



GENERAL AND OSTEOPATHIC 179 

inhibiting the peristaltic wave. The method by means of 
which it does this will be discussed later. 

Large Intestine. — There probably is no one segment of 
the spinal region which is directly responsible for the cause of 
constipation or diarrhea, but the results are largely due to the 
fact that the lesion interferes with the normal movements and 
secretions of the large intestine, which, as already explained, 
might cause the contents of the gut to be retained in the colon, 
the result being bacterial fermentation and the formation of 
gas, causing excessive distension and irritation. This excessive 
irritation results in over-stimulation of the afferent nerves from 
the intestine and this causes excessive stimulation of efferent 
fibers, thereby causing a continued perversion of function. 

The Effects of Spinal Treatment. — The correction of a 
lesion causative of such conditions normalizes the nerve supply. 
This in turn normalizes the blood supply and venous drainage 
and lymph supply and drainage to the structure involved, and 
normal function results. That is the mechanism by means of 
which osteopathic treatment is effective in these conditions. In 
case there is an osteopathic lesion interfering with the normal 
functions of the intestine, one might do almost anything else in 
the way of treatment without success. 

Experimental Evidence. — Bony lesions when produced 
in the lower dorsal or lumbar spines of monkeys cause abnormal 
functions of the intestines, usually diarrhea, in from 24 to 48 
hours. If after a few days the lesion be corrected- the trouble 
ceases. This has been repeated several times on the same animal 
with similar results, but after several lesions have been produced 
at different times in the same animal treatment fails to relieve 
the symptoms. (Series No. 12.) 

Dorsal and lumbar lesions in dogs have been shown to be 
causative factors of intestinal disturbances. (Series No. 4.) 
Sacral and innominate lesions also may cause intestinal troubles. 
(Series No. 13.) 



180 physiology: 

THE SLPEEN. 

There is little known about the functions of the spleen, regard- 
less of the many theories that have been advanced. The spleen 
can be removed from an animal without causing serious injury. 
After extirpation certain changes have been observed such as an 
increased growth of the lymph glands, an increased growth of 
bone marrow, a diminution in the normal number of red cells, 
and a general decrease in the quantity of hemoglobin, but these 
results have not been confirmed by all workers on the subject. 

The following theories of the function of the spleen have 
been advanced : 1 . That it is in some way related to the function 
of red blood corpuscles ; 2. that it is concerned with the regenera- 
tion of blood after hemorrhage. It is known that the spleen 
functions as an embryonic hematopoietic organ — that is it takes 
part as does the liver, in the formation of blood elements in the 
foetus before birth and probably for a short time after birth; 3. 
that it may be concerned with the formation of hemoglobin; 4. 
that it may be concerned with the destruction of red corpuscles; 
5. that it may take part in the formation of uric acid by the 
action of certain enzymes on nucleins ; 6. that the spleen produces 
a substance, probably an enzyme, which activates the trypsinogen 
of pancreatic juice. 

Expansions and contractions of the spleen, the so-called 
splenic pulsations, have been noted during digestion, which are 
probably due to vaso-dilation and possibly to muscular contraction. 
The function of such movements is not known. 

The spleen has no duct emptying into the alimentary canal 
like the pancreas and liver, but has a good blood supply and 
therefore its secretions, if any, are internal. The spleen receives 
a rich nerve supply of splanchnic fibers, probably vaso-dilators, 
vaso-constrictors, and trophic. 




\ " ,-#* : ^-U 



Plate XXI. — Portal circulation to the liver, including blood from spleen, pancreas, 
stomach, and intestines: 1, Inferior vena cava; 2, 2, ligaments to support liver; 3, 3, transverse 
colon; 4, hepatic flexure; 5, splenic flexure; 6, ascending colon; 7, descending colon; 8, portal 
vein entering liver; 9, superior mesenteric vein; O, gastro ep. dextra vein (from stomach); 10, 
inferior mesenteric vein; 11, gastro ep. sinistra (from stomach); 12, splenic vein; 13, coronary 
(from stomach); 14, left colic vein; 16, 16, right colic branches; 17, ileo-colic; 18, appendiceal 
vein; 19, superior hemorrhoidal; 20, caecum; 21, appendix; 22, sigmoid vein; 23, sigmoid 
flexure; 4 L., fourth lumbar; 5 L, fifth lumbar. 



CHAPTER XVIII. 
EXCRETORY ORGANS. 

The Kidneys. — It is expected that students who use this 
book will review the histology and anatomy of the structure studied 
from their texts on these subjects, therefore no lengthy discussion 
will be given. From a study of the histology of the kidney it 
will be seen that there are structures which are seemingly adapted 
to filtration (the glomeruli) and other structures adapted for 
secretion (uriniferous tubules). 

Nerve Supply. — It has been shown that the kidneys receive 
a rich nerve supply from the splanchnics which probably originate 
from the lower dorsal and upper lumbar segments of the cord. 
It is stated that stimulation of these nerves results in vaso- 
constriction of the small arteries of the kidney, a reduction in the 
size of the organ, and a diminished secretion of urine, while cutting 
these fibers seems to result in vaso dilation due to loss of tone to the 
vessel walls, which is followed by an increase in the flow of urine. 
(See osteopathic experiments). 

It is generally supposed that these fibers regulate the flow 
of urine by reflex; that is, by the regulation of the blood supply 
of the kidney. Bradford has shown that vaso-dilator fibers from 
the lower thoracic segments of the cord supply the kidney, which 
when stimulated increase the flow of urine reflexly. Afferent 
fibers are probably present in these nerves which enter into the 
reflex mechanism. Secretory nerves have not been demonstrated. 

Formation of Urine in the Kidneys. — Since secretory 
nerves to the kidney have not been demonstrated it is generally 
conceded that the formation of urine is effected by changes in the 
blood supply ; that is, that the secretion of urine, like the secretion 

181 



182 physiology: 

of bile, varies directly with the blood supply. (See osteopathic 
considerations.) 

Two general theories have been advanced relative to the 
formation of urine, viz., secretion, and secretion and diffusion. 
Evidence in favor of the latter theory is as follows: 

1 . The structure of the glomeruli is such that filtration would 
seem probable and according to Ludwig such substances as inor- 
ganic salts, urea, water, etc., were so produced from the blood. 
According to this theory it was supposed that other substances of 
the urine came from the tubules by a process of diffusion. The 
theory of Bowman and Heidenhain was similar to that of Ludwig 
except that they held that the glomeruli produced water and 
inorganic salts and the urea and other substances were produced 
by the epithelial cells of the convoluted tubules by a method of 
selective absorption. The work of the epithelial cells is explained 
by attributing to them the function of selective absorption, which 
was supposed to be due to some special function of these cells. 
Whether this is the true explanation has never been demonstrated, 
but most authorities now consider the functions of the tubules 
as secretory rather than as stated above. 

2. Since secretory nerves have not been demonstrated and 
since there is good evidence to show that the formation of urine 
is increased by an increased blood supply to the kidney, this is 
further reason for believing in the filtration theory. The increased 
pressure caused in the kidney by blocking the venous drainage 
is not followed by increased secretion, but this is insufficient 
argument against the theory of filtration. The theory of Heiden- 
hain as given above seems to be more in harmony with the experi- 
mental evidence. 

3. The capillary pressure in the kidney is from 50 to 75 m. m. 
of Hg, which fact would seem to favor the filtration theory. 

4. It has been shown in the extirpated kidney that if water 
pressure be connected to the renal artery it will flow through the 
kidney and into the ureters (Soleman), but this is not of great 
significance. 



GENEKAL AND OSTEOPATHIC. 183 

5. It has been shown that either the tubules or glomeruli 
can secrete normal urine. (Meisbaum's experiment.) 

Secretion Theory. — The evidence adduced in favor of 
the secretion theory is as follows: 

1. The rate of urine formation is increased as the rate of 
blood-flow through the kidney is increased. The rate of flow 
would not necessarily influence filtration. It is supposed that 
the arterial blood may stimulate the secretory cells and thus 
increase the formation of urine. 

2. After injection of certain substances into the blood stream 
(indigo carmine) granules of these substances may be found in 
the epithelial cells of the convoluted tubules, showing that these 
cells seem to have the power of separating these substances from 
the blood. 

3. It has been shown that iron, uric acid, and some other 
substances are separated from the blood by the epithelium of the 
tubules. 

4. The fact that sugar is normally present in the blood and 
is normally absent in the urine has been used as argument against 
the filtration theory. 

5. It would seem that the histological structure of the tubules 
is best adapted for secretion. 

6. There is some reason to believe that diuretics cause the 
increase in urine formation by stimulating the secretory cells 
directly. There is no doubt that certain diuretics such as digitalis, 
caffeine, etc., will produce an increased flow of urine, but there 
are many other substances, such as dextrose, urea, and certain 
organic salts which will do this, and as yet no satisfactory explana- 
tion of their action has been given. Water is probably the best 
of all diuretics. 

To summarize, it may be said that no conclusion can be 
reached from the experimental evidence at hand, but that both 
factors, secretion and filtration, probably play important parts 
in the formation of urine. It has been shown by Schafer that a 
substance (internal secretion) produced by the nerve portion of 
the pituitary body acts as an active diuretic. 



184 



physiology: 



Properties and Constituents of Urine as Compared with 




Blood. 




Urine Blood 


Color 


Yellowish (variable) Scarlet or purple (variable) 


Specific gravity 


1.020 (average) 1.055 (average) 


Reaction 


Normally acid, due to acid Neutral or slightly alkaline 




phosphates 


Urea 


2% (variable) .02— .04% 


Inorganic salts 


1.5 % (variable) .85% 


Proteins 


A trace only Variable amounts 


Sugar 


Normally absent .09 — .2% (almost constant) 



Kidney Excretions. — The following is a list taken from 
Starling showing the average elimination in 24 hours of an adult 
man on ordinary mixed diet. Total amount of urine, 1,500 c.c. 
This contains about 60 gm. of salts, of which 25 gm. are inorganic 
and 35 gm. organic. These are distributed as follows (Starling, 
p. 1242): 



Inorganic Constituents. 

Sodium chlorids 15.0 grm, 

Sulphuric acid 2.5 " 

Phosphoric acid 2.5 " 

Potassium 3.3 " 

Ammonia 0.7 " 

Magnesia 0.5 " 

Lime 0.3 " 

Other substances 0.2 " 



Organic Constituents. 

Urea 30 . grm. 

Uric acid 0.7 " 

Creatinine 1.0 " 

Hippuric acid 0.7 " 

Other substances ........2.6 " 



The kidneys are the chief excretory organs for nitrogen, which 
is eliminated chiefly in the form of urea. The chemistry of the 
process, as well as other products given above, is to be found in 
texts on physiological chemistry. 

Water Elimination. — There are three main channels, viz., the 
kidneys, the skin, and the lungs, a small portion being eliminated 
by way of the rectum. The greatest amount of water is eliminated 
through the kidneys (average, 1,500 to 1,700 c. c. daily for an 
adult man). This quantity varies inversely with the amount 
eliminated by the other channels, especially the skin. If there 
is much sweat (under certain conditions it may be as great as or 
even exceed the kidney elimination) the urine is decreased in 
amount and increased in its solid content. 

Micturition.- — The formation of urine in the kidney is a 
constant process (from one to five drops per minute for each kidney) 



Plate XXII.— 
Showing blood sup- 
ply to the ascending 
colon, also its rela- 
tion to the liver: 1, 
Descending aorta ; 
2, ganglia of the 
lateral chain; 3, 
veins of liver; 4, por- 
tal vein entering the 
liver; 5, beginning 
of the transverse 
colon; 6, arteries 
and veins of the co- 
lon; 7, superior mes- 
enteric vein; 8, su- 
perior mesenteric 
artery; 9, right colic 
vein; 10, ascending 
colon showing blood 
supply; 11, branch 
of superior mesen- 
teric artery ; 12, 
nerves of lumbar 
plexus; 13, ileum at 
point of entrance 
into caecum; 14, 
caecum; 15, appen- 
dix; 16, sacral part 
of lateral chain gan- 
glia; 17, coccygeal 
ganglion. 




GENERAL AND OSTEOPATHIC 185 

and it is carried to the bladder by the ureters, which perform this 
function by peristalsis of its smooth-muscle walls. Whether 
this peristalsis which moves at rather regular intervals from the 
kidney to the bladder is regulated by extrinsic or intrinsic nerve 
mechanism, or whether it is due to automaticity of its muculature, 
has not been determined. Gravity plays no essential part in 
the process. The bladder dilates to accommodate the increasing 
quantity of urine, which is finally discharged from the bladder 
through the urethra. 

The Bladder.- — The bladder wall consists of three muscular 
coats — middle, circular, and inner and outer longitudinal. Two 
sphincters of the urethra, an internal and an external, which con- 
sist of augmentations of the circular fibers at these points, regulate 
the discharge of urine from the bladder. The tonic contractions 
of the internal sphincter, aided by the elasticity, are the causes 
of retention of urine until proper time for its discharge. The 
discharge of urine is normally under voluntary control, but is 
probably regulated by reflex in children and to some extent in 
adults. There is experimental evidence to show that the discharge 
of urine in dogs is regulated almost wholly by reflex. 

Nerve Supply of the Bladder. — Viscero-motor fibers caus- 
ing constriction of the bladder are supplied by the hypogastric 
nerves and plexuses from the inferior mesenteric ganglion. These 
fibers come from the second, third, and fourth lumbar segments 
of the cord. The chief viscero-motor fibers of the bladder walls 
are supplied from the sacral segments, third, fourth, and fifth. 
Sensory fibers to the walls of the bladder are supplied by the 
hypogastric nerves and the sacral nerves. (Landois.) The 
vesico-spinal center for reflex stimulation of the bladder is located 
about the fourth lumbar segment of the spine. Evacuation of 
urine may also be caused by stimulation of other sensory nerves. 
The urethro-spinal center is located about the fifth lumbar segment 
of the spine. (Landois.) The reflex mechanism of this center 
probably plays some important part in the act of micturition. 
The same author states that "From the cerebral cortex the volun- 
tary motor paths course downward through the spinal cord to 



186 physiology: 

the sphincter muscle of the urethra, within the pyramidal tracts." 
Similar cortical paths are claimed to exist for other visceral func- 
tions, but this is not generally confirmed by other physiologists. 
There is, however, much evidence to show that there is some 
connecting nerve mechansim between the centers regulating these 
functions and the cortex, but the connecting pathways are not 
known. 

Osteopathic Considerations. — It has been shown, Series 
4 and 12, that bony lesions of the lower thoracic and upper lumbar 
regions produced artificially in normal animals affect the normal 
functions of the kidneys. Clinically many cases of kidney 
trouble have been demonstrated to be due to similar lesions. 

In Series No. 16, Pengra and Alexander have conclusively 
shown that the secretions of the kidneys can be increased from 
25 to 100% by stimulatory treatment applied to the eleventh 
and twelfth thoracic segments of the spine. The secretion thus 
produced often remains increased for two or three hours or longer, 
during which time the water content of the body is greatly reduced. 
This same experiment has been tried with equal success on the 
human, and by this means in cases of febrile conditions the toxins 
of the body fluids and the temperature have been much reduced 
in a number of cases in which the test has been applied. 

The practical significance of such treatment is therefore 
apparent. If the toxin content of the blood can be materially 
reduced, as this experimental evidence shows it can be, this is a 
very efficient method of treatment in infectious fevers. Spinal 
manipulation which produces free movement between the verte- 
brae named should be continued for ten or fifteen minutes at each 
treatment and several such treatments given daily during the 
febrile state. Dr. McConnell has shown that bony lesions of the 
mid and lower dorsal regions are followed by pathological lesions 
of the kidney. 



! 



GENERAL AND OSTEOPATHIC. 187 

THE SKIN. 

The functions of the skin are many and varied. 

1. It forms a sensory receptor surface for the adjustment 
of internal functional activities to external environment by means 
of nerve-reflex mechanism. There are a great many specifically 
receptive surfaces supplied by specific afferent nerve fibers, such 
as pressure, temperature, pain, and many others, the specific 
afferent associations of which assist in the regulation of body 
adjustment to the demands of function. 

2. The regulation of body temperature which is affected 
by the production of sweat and the cooling of the blood by peri- 
pheral vaso-dilation. 

3. The formation of certain essential secretions such as 
sweat, sebum and milk, the mammary glands being modified 
glands of the skin. 

4. Another function, that of protection to the underlying- 
structures, is ascribed to the skin. 

5. It is an established fact that watery solutions are not 
absorbed by normal skin, therefore the fallacy of the so-called 
medicinal baths. Mud is surely no more soluble than water. 
There are certain substances which may be absorbed to some 
extent in the form of fatty inunctions, but cod-liver oil, for example, 
is not absorbed in sufficient quantities to be highly nutritious. 

6. As an organ of excretion two sets of glands are to be studied, 
viz., sweat glands and sebaceous glands. 

Sweat Glands. — Sweat may properly be termed a secretion 
and an excretion. As an excretion it reduces the body water 
content and throws off some other substances. (See contents 
below.) Secretory glands for the production of the perspiration 
may be found in all skin surfaces except the glans penis, the prepuce 
and the external auditory meatus. These glands are found in 
greatest numbers on the soles of the feet and the palms of the 
hands. The secretion produced by these glands varies from 500 
c. c. to 1,000 c. c. daily, the amount being influenced by many 
conditions, e. g., temperature of the body, temperature of the 



188 physiology: 

environment, muscular exercise, and psychic conditions. There 
are certain infectious fevers, the toxins of which by their effect 
on the thermogenic and vasomotor centers influence sweating. 
In general it may be said that the activities of the kidneys and 
skin vary in an inverse ratio; that is, if the kidneys are 
highly functional the secretion of sweat by means of the skin is 
decreased, and the converse is also true. In summer there is 
a greater amount of sweat produced and a comparatively smaller 
amount of secretion from the kidneys, if the water intake is con- 
stant. 

General Properties and Constituents of Sweat. — Sweat 
is a clear, colorless fluid. When first secreted it is alkaline, later 
becoming acid in reaction, has a specific gravity of 1.003, and 
contains the following substances: water, 99%; sodium chloride 
and other inorganic salts, 0.3 to 0.6%; proteins, a trace; urea, 
a trace. 

Secretory Nerves. — That the secretion of sweat is regulated 
by the central nervous system, both directly and reflexly, has 
been conclusively shown experimentally. If the sciatic nerve 
be cut in one leg of a cat and the animal be placed in an incubator, 
the temperature of which is kept slightly above normal, sweat 
will appear on the pads of the feet, but not on the one the nerve 
of which has been sectioned. The most probable explanation is 
that the increased temperature of the blood (from .5° C. to 1° C. 
above normal is sufficient) stimulates the nerve centers controlling 
this function to increased activity. The same explanation holds 
for increased sweating caused by the Turkish bath. It has been 
shown that warming of the blood of the carotid arteries and 
asphyxia may increase the secretion of sweat, which would seem 
to be evidence of a sweat center in the medulla, but no positive 
proof of such center exists. 

Stimulation of the peripheral end of the sciatic nerve in a 
freshly amputated limb of a cat causes the formation of sweat 
droplets on the pads of the foot, which shows that the secretion 
may be affected by direct stimulation. The sweating which 
results from stimulation of the central ends of afferent or mixed 



; 

I 



GENERAL AND OSTEOPATHIC. 189 

nerves may be attributed to reflex effects, probably due to vaso- 
motor changes, in the structures supplied. The sweat-nerves 
pass to the structures via the spinal autonomics originating from 
the second thoracic to the fourth lumbar. (Langley.) 

Cutaneous Respiration. — C0 2 is given off from the skin 
in variable quantities, varying from 6 gms. to 10 gm.s. in 24 hours. 
If there is much sweating the amount is much increased. There 
is probably a very small amount of oxygen taken in through the 
skin in the human, but in some animals (the frog) the skin may 
function as an essential respiratory organ. 

Secretion of Sebum. — The ducts of the sebaceous glands 
for the most part empty in common with the hair follicles. The 
secretions of these glands consist of cell detritus, formed from, the 
degenerated cells of the sebaceous glands. Sebum consists of 
fats, soaps, albuminous material, etc., and is collected from some 
animals (sheep) and made into a commercial preparation, lanolin, 
which, because of the fact that it does not melt readily at body 
temperature, makes an excellent application for erythematous 
eruptions. Other forms of sebum are smegma, formed by the 
prepuce, cerumen (ear wax) of the external auditory meatus, 
and vernix caseosa, the cheese-like covering of the foetus. The 
function of sebum is protection of skin and hair, and as an excretion 
it rids the skin of cell detritus. 

Osteopathic Considerations. — Bony or muscular lesions, 
particularly of the upper thoracic region, have been shown clinically 
to affect sweat secretion; and that spinal treatment will increase 
the flow of sweat has been demonstrated. The reduction of 
fever temperature by osteopathic treatment may properly be 
ascribed to the increased elimination by means of sweat secretion. 



I 



SECTION IV 



METABOLISiM AND BODY 
ENERGY 



CHAPTER XIX. 

PROTEIN AND CARBOHYDRATE 
METABOLISM. 

Quantitative analysis of the protein molecule shows it to 
contain about sixteen per cent of nitrogen. The study of protein 
metabolism therefore concerns chiefly the nitrogen changes, and to 
determine the protein metabolism in the body, an estimation of 
the nitrogen content of the food ingested during a certain period 
and an estimation of the nitrogen content of the excreta — urine, 
sweat and feces — will show whether the animal is losing, gaining, 
or remaining constant. If the nitrogen content of the excreta 
is the same as that of the food ingested, the animal is said to be in 
a state of nitrogen equilibrium. If the nitrogen excreted is greater 
than that ingested, the individual is in a state of nitrogen minus, 
and if the nitrogen intake is greater than the amount excreted, the 
individual is in a state of nitrogen plus, which means that the 
individual is storing proteins. 

In the growing individual and during convalescence from 
infectious diseases, etc., the body is in a condition of nitrogen 
plus. In starvation, old age, and during the active stages of 
certain diseases the body is in a state of nitrogen minus, while 
during the period of adult life on nomral diet the protein metabo- 
lism is in balance or nitrogen equilibrium. 

The same comparisons may be made for the carbohydrates, 
by determining the carbon content in the C0 2 , urine, etc. excreted 
in proportion to the carbon intake. Under normal conditions 
in adult life, the carbon is also in equilibrium. 

By reference to the chapter on foods it will be seen that the 
various food stuffs have more or less specific functions, viz. : The 
proteins build tissue and the carbohydrates and fats furnish energy 

193 



194 physiology: 

for heat, work, etc. It may be seen that the body may vary in 
these respects according to the metabolism of the various foods; 
that is, one kind of food might be in equilibrium while another 
oould be either minus or plus, or they may all be in equilibrium, 
in which condition the body is said to be in complete balance. 
This condition may also be determined by a complete analysis 
of the food and air taken in, and the excreta, including the expired 
air, given off. The respiration chamber, to be described later, 
is used for this purpose. 

Amount of Protein Necessary. — The average individual, 
according to Howell, uses from 100 to 120 grams of protein daily. 
About 100 grams are used and the rest thrown off in the excreta. 
Various workers in physiological research have endeavored to deter- 
mine the amount actually needed, and the noteworthy researches 
■of Chittenden (his results may be found in his book, "Nutrition 
of Man") have shown that the protein food may be much reduced 
without reducing the individual's physical or mental powers. 
His results show that complete efficiency can be maintained on 
from 30 to 50 grams of protein daily. Chittenden himself and 
many of his Yale students experimented upon and did well on a 
much less amount than this. Some college athletes seemed to 
liave an actual increase in energy on 50 grams or less daily. He 
claims that an excess of proteins taken in diet means only useless 
work in digestion, and therefore a decreased resistance and 
^efficiency. The question here arises relative to the long continued 
use of such a diet. It is known that men engaged in hard work 
take more protein and seem to do well on such a diet, and while 
the results given by Chittenden are quite conclusive, we are inclined 
to question whether they would stand a practical, long continued 
test. 

Protein Sparers. — It is known that a state of nitrogen equilib- 
rium may be maintained on a comparatively small amount of pro- 
tein foods if other foods — carbohydrates and fats — in plentiful 
amounts be given in the diet. These foods are therefore known 
as protein sparers, as they seem to lessen the demand for preoteins 
The explanation is that the protein foods must have two functions 



GENERAL AND OSTEOPATHIC. 195 

First, tissue builders; second, supply of energy to living tissues. 
If then, this second function can be replaced by the carbohydrates 
and fats which are known to have the power of yielding energy 
the proteins would be left to perform the one and their chief func- 
tion, that of tissue building, and therefore a much less amount 
would be needed. 

CARBOHYDRATE METABOLISM. 

As has been stated in the chapters on digestion and absorption, 
the starchy foods are reduced to soluble sugars, in which form 
they are carried to the liver by the portal vein and stored in the 
liver in the form of glycogen. The liver glycogen, then, furnishes 
the chief source of carbohydrates for the use of the body as it is 
needed. The liver may vary greatly in its glycogen content 
from possibly 4% or 5% to 15% or even more, while the other 
organs concerned in carbohydrate metabolism remain rather 
constant in their sugar content. The sugar of the blood is always 
normally from .1% to .2%. The glycogen content of muscle is 
variable, but much more constant than in the liver. In the foetus 
and young child the muscle may serve as a glycogen storer, but in 
the adult, muscle contains from .4% to 1% of glycogen. 

Carbohydrates are carried in the blood in the form of soluble 
sugar (dextrose) and are re-stored in the muscles as glycogen. 
This change in the carbohydrates is necessary, and is probably 
effected by some enzyme action in the liver and muscle. By 
this method the liver is constantly furnishing the supply of carbo- 
hydrate material for the various structures of the body when 
needed. Other structures such as the pancreas, as has been 
stated, are concerned in the metabolism of the carbohydrates. 
The function of these regulators of carbohydrate metabolism are 
to some extent under the control of the nervous system, and there- 
fore any inefficiency of this system may materially affect these 
functions. It has been shown that puncture of the medulla affects 
carbohydrate metabolism, and there is supposed to be a center 
for the regulation of such functions located there. If the splanch- 



196 physiology: 

nic nerves be sectioned, or if the cord be cut above the fourth 
dorsal segment no glycosuria results from puncture of the medulla, 
which would seem to show that some spinal-cord mechanism is 
involved in the function of those structures which regulate carbo- 
hydrate metabolism. Attention has also been called to the unity 
of functional activity of the " splanchnic triad" — the liver, duo- 
denum and pancreas and how the normal functions of one depend 
upon the others. Any of these structures, then, may be concerned 
with this storing and regulating of the carbohydrates. If for 
any reason the sugars of the blood are not reduced to glycogen 
and properly stored by the liver or muscles, a condition of hyper- 
glycemia (excess of sugar in the blood) follows and as this must 
be excreted by the kidneys, glycosuria or sugar in the urine results, 
and because of this the body suffers from lack of this foodstuff as 
a heat and energy producer, and therefore body energy and resist- 
ance are both reduced. The disease diabetes mellitus is charac- 
terized by glycosuria, polyuria, loss of weight and energy, and 
reduced resistance to other diseases. It may therefore be seen 
that the normal function of all structures concerned in carbo- 
hydrate metabolism is very essential to health. 

Normal carbohydrate metabolism may be affected, causing 
glycosuria, in the following ways: 1. Puncture or other lesion of 
the medulla; 2. Stimulation of the vagus or, indeed, any lesion 
affecting any sensory nerve; 3. Pathological lesions of the spinal 
cord; 4. Any deficiency of the functions of the pancreas, whether 
by degeneration or other pathological lesion or by an interference 
with its nerve supply; 5. Any deficiency in the normal functions 
of the liver or muscles which renders them unable to change the 
sugars and store the glycogen. To this list of causes given in 
general physiology may be added the osteopathic lesions, viz. : 6. 
Any visceral lesion interfering with the functions of the pancreas, 
liver, duodenum, kidney, etc., or the nerve supply to these organs, 
and 7. Bony lesions of the mid and lower dorsal regions. (See 
series 4, and series 12.) 

In diabetes mellitus not only are the carbohydrate foods 
not utilized, but even the proteins are reduced to sugar and elimi- 
nated; thus the loss of tissue building function and the emanciation. 



GENERAL AND OSTEOPATHIC. 197 

Functions of the Carbohydrates. — These foods have 
several important functions, as follows: 1. They may act as pro- 
tein sparers, as described above; 2. They furnish energy for 
muscle activity, etc.; 3. They provide heat by oxidation, and 
4. An excess of carbohydrate material may be reduced to fat and 
stored in the body as such. The changes by which this is effected 
are not known, but there is ample evidence that it does occur. 



CHAPTER XX. 

METABOLISM OF FATS AND ACCESSORY 

FOODS. 

To understand the history of the metabolism of fats it is 
necessary to review the changes in digestion and absorption. 
Fats are taken from the blood and lymph into the tissue by some 
process of selective absorption peculiar to the tissue cells. Oxidi- 
zation of these fats results in the production of C0 2 , water, energy, 
and heat. 

Functions of Fat in the Body. — 1. As given, oxidation 
results in heat and energy; 2. Fats may be stored as a reserve 
supply and for protection, etc; 3. Fat products may be changed 
to other substances, such as lecithin; 4. It may function as a 
protein sparer, and 5. There is evidence to show that it may 
under some conditions be changed to sugar. 

Source of Fats in the Body. — It is probable that the carbo- 
hydrates furnish the chief source of fats. Some fats come from 
the animal and vegetable fats taken in the diet, and some from 
the proteins. In the case of animal fats they may be stored in 
the same form as eaten. 

Individual Variation. — There is little known about the 
causes which underlie fat desposition in the body, and only general 
reasons can be given. The chief cause of fat deposit in those 
individuals who live a normal life with sufficient exercise is the 
inability of the system to destroy the food material taken. Fats 
are destroyed chiefly by oxidation, and it is probable that there 
is a lack of certain internal secretions which effect fat oxidation. 
It is known that the ovaries and testes play an important role 
in this function, and that after extirpation of the ovaries in animals 
and after the menopause in women there is a tendency to lay on fat. 
198 



GENERAL AND OSTEOPATHIC. 199 

Various theories have been given, e. g., hereditary tendencies,, 
individual variations, etc., none of which have any particular 
significance, but for the average individual the following factors 
play important parts in his fat metabolism: Rest is always 
essential to fat deposition, and the sedentary lives of many is 
perhaps responsible for their excessive weight; activity and fat 
formation vary inversely, but this is limited; alcoholism often 
results in fat deposition, the oxidation of the alcohol protecting 
the fats. In that way it acts as a fat sparer. 

Inorganic Salts. — Body ash consists essentially of the 
chlorides, phosphates, carbonates, fluorides, salicylates, sulphates, 
etc., of calcium, magnesium, potassium and a few other metals 
in traces. 

The functions of the inorganic salts are as follows: 

1. Maintenance of constant density of body fluids; 2. some 
have specific functions, such as calcium salts in blood clotting and 
milk curdling, iron in assisting hemoglobin in its oxygen carrying 
power, iodine, calcium, and possibly others in certain internal 
secretions, and again it seems that certain salts are necessary 
to the vital functions of certain cells. The irritability of muscle 
and nerve cells, for example, seem to be increased by the action 
of calcium salts. 

ACCESSORY FOODS. 

Stimulants. — The effects of secretogogues from the meat 
extracts, soups, etc., have been discussed elsewhere. They con- 
stitute normal stimulants to gastric secretion. 

Coffee and Tea effect stimulation by their proximate prin- 
ciple, caffeine. It is considered as a nerve stimulant, increasing 
blood pressure; a stomachic tonic, slightly laxative and diuretic, 
and is injurious only in excessive quantities, the dose of the drug 
being from one to three grains. Large amounts of coffee diminish 
fatigue and prevent sleep. 

Cocoa and Chocolate contain much nourishment. The alka- 
loid theo-bromin is a stimulant, but not in any way detrimental in 
ordinary quantities. Twenty to thirty grams may be used daily. 



200 PHYSIOLOGY : 

Alcohol in small amounts stimulates secretion and absorption, 
and may be of some benefit in the aged. It is also a protein, carbo- 
hydrate and fat sparer, and may properly be considered a food in 
these respects. The evil effects of alcohol come only from the 
excessive use or the cultivation of the habit. It has been demon- 
strated that the use of alcohol in excess for long periods results in 
pathological changes in the stomach, heart, liver, nervous system, 
etc. Conditions of acute troubles may also result from single 
overdoses of alcohol. For these reasons alcohol cannot be con- 
sidered a practical food. Alcohol acts as a paralyzant on the 
inhibitory motor centers, and in this way causes the apparent 
increase in muscular efficiency. In small quantities it is not a 
heart stimulant, but causes peripheral vaso-dilation in any quan- 
tity and in this way causes loss of energy and body cooling, but 
these effects are not lasting. 

Condiments, Flavors, etc. — Nothing can be said against 
the moderate use of these substances. They often hasten diges- 
tion and secretion, and enable the individual to eat well. By the 
stimulation of the " appetite juice" — the so-called psychic secre- 
tion — and by increasing the appetite, these substances often 
do much good. 



CHAPTER XXI. 
BODY ENERGY. 

In previous chapters in the discussion of the various functions 
of foods it has been stated that the carbohydrates and fats furnish 
the chief source of body energy. The energy yielded to the body 
by these foods comes from a breaking down of the complex chemi- 
cal compounds, chiefly by a process of oxidation. Such reactions 
result in the formation of simpler compounds and energy. The 
energy may be in one or more of several forms. The result of 
such an action may be compared to the discharge of powder in a 
gun. For example, the stimulus by way of a nerve may be com- 
pared to the primer which ignites the powder. The reduction 
of the complex organic compounds to the simpler products may 
be compared to the quick combustion of the nitrates and sulphates 
of the powder to their simpler forms. The energy yielded which 
does work in moving muscle, producing nerve force, etc., may 
likewise be compared to the energy yielded which drives the shot, 
and the heat energy which results, causing an increase in the 
body temperature, etc., with the heat energy which accompanies 
the powder explosion. It is in each case a result of an exothermic 
chemical change produced by the chemical reaction. 

Man is a machine in the strictest sense, and in no phase of 
mechanics do the laws of the conversation and transformation of 
energy hold more true. The source of energy in the animal is 
the complex chemical compounds of plants and other animals 
which it takes in the form of food. The animal has no power 
to generate energy within its own body. The only thing it can 
do is to transform this potential energy of the complex compounds 
into other forms useful to itself. These compounds when properly 
transformed are again like the powder charge in the gun; they 

201 



202 • PHYSIOLOGY : 

constitute the potential energy which may at will, as in case of 
the carbohydrate supply of voluntary muscle, be converted into 
kinetic or active energy by the function of the nerve impulse 
supplying the structure. The study of digestion and metabolism, 
then, becomes a study of the transformation of energy. 

The forms of energy resulting may be many and varied. 
For example, the energy to move muscle, the energy causing 
secretion, the energy which furnishes the cell with its power of 
specific function, the energy giving origin to nerve force, electrical 
energy which probably influences chemical changes, the heat 
energy which results from exothermic chemical changes and to 
some extent from friction, all have their various functions. In 
the law of conservation of energy we also have an important 
lesson for physiological study: Energy can be transformed but 
not generated. The animal must get his supply of energy from 
his foods. 

During the many years of structural adaptation the animal 
has developed its machinery to the highest degree of efficiency. 

In mechanics' efficiency = — - — — . It has been 

force applied (dynes) 

found that in the case of men doing work such as mountain climb- 
ing, from 35% to 40% of the energy yielded from oxidation of 
foods is utilized in work done. (Work = force applied through a 
distance.) By comparing this efficiency with that of machines 
(engines utilize from 15% to 25%) it will be seen that the human 
machine is most excellently adapted for the work which it has 
to do. 

Measurement of the Body Energies. — The Atwater 
respiration calorimeter chamber is a device used for the study of 
the energy of man. It consists of an air-tight, heat-tight chamber 
sufficiently large for the individual to live in for a length of 
time. It is so arranged that the oxygen and C0 2 content of air 
breathed and the oxygen and C0 2 content of the expired air 
may be determined. The heat equivalent of the food eaten may 
be determined by oxidizing, and the heat equivalent of the excreta 
may be determined in the same way. By placing a machine in 



GENERAL AND OSTEOPATHIC. 203 

the chamber upon which the man may do work and have this 
work recorded, for which purpose a bicycle ergometer is used and 
the estimations made as follows, accurate results may be obtained: 

1 . Heat equivalent of total amount of food taken determined. 

2. Excreta collected and completely oxidized and this 
deducted from (1). 

3. C0 2 collected and calculated. 

4. Work recorded on bicycle ergometer measured. 
Calculation : 

1 — 2 = amount of heat from food by body; 

3 — |- 4 = total amount of oxidation and work done; 

Therefore 1 — 2=3 + 4. 



CHAPTER XXII. 
BODY ENERGY AND BODY TEMPERATURE. 

Source of Body Heat. — The chief source of heat energy 
in the body is the oxidation changes. These changes for the 
most part occur within the living cells, giving functional energy 
to the cells and increasing the chemical changes in and about the 
cell. It is known that chemical changes, metabolic in nature, 
are increased by an increase in temperature in the body just as 
they are "in vitrio. " Friction of the blood as it moves in the 
vessels is responsible for only a very small part of the body-heat 
production, and friction of the muscles results in the production 
of a much less amount of heat energy. The temperature of the 
food ingested, as in case of hot drinks, etc., may in some instances 
increase the total body temperature. 

Heat Production, How Regulated. — It may readily be 
seen that this is an important factor in body metabolism, as so 
much depends upon the influence of heat production. Several 
factors are concerned, such as 

1. The quantity of food. 

2. The kind of food taken, some yielding more heat energy 
than others. 

3. The activity of skeletal muscle. 

4. Influence of nerve-regulating mechanism, such as the 
vasomotors which regulate the blood supply, and by their trophic 
effects regulate cellular metabolism. 

Muscular Exercise. — That muscular exercise increases the 
demand for food and the amount used in metabolism has been 
demonstrated scientifically. Several theories have been advanced 
to explain this, some of which will be briefly given: Liebig has 
advanced the theory of two general functions of food, viz., oxida- 
204 



GENEKAL AND OSTEOPATHIC. 205 

tion for the supply of heat, which function is fulfilled by the 
carbohydrates and fats, and the other main function, that of 
tissue building, which is effected by the proteins. Since muscle 
tissue, according to this theory, needs protein for tissue building, 
it was assumed that protein foods furnished the chief source of 
energy for muscular work. It was conclusively proven by Fick 
and Wislicenus in tests made on themselves while mountain climb- 
ing, during which time they used a non-protein diet, that certainly 
not all the energy for muscular work came from protein oxidation. 
Voit has further shown by experiments on man, using the respira- 
tion chamber, that moderate muscular exercise does not affect 
the protein oxidation. It has now been conclusively shown that 
the non-protein foods are responsible for the source of energy for 
muscular work, but if the muscular work be excessive there is 
some wear of the muscle tissue which can only be repaired by 
protein food. 

Regulation ol Loss of Body Heat. — About 73% of the 
total loss of heat is by radiation, which is regulated by clothing 
and the temperature of the surrounding air. 

Evaporation of moisture from the skin, which is determined 
to some extent b}^ clothing but principally by the vasomotor 
mechanism, is also responsible for a large amount of loss of body 
heat. This excessive secretion of sweat is effected in one or more 
of several ways: 

1. By vaso-dilation, caused possibly by direct or reflex stimu- 
lation of vaso-dilator centers, and 

2. Vaso-dilation caused by direct or reflex inhibition of the 
vaso-constrictor centers. 

3. Direct or reflex stimulation of some specificnerves regulat- 
ing sweat secretion, as described under the secretion of sweat. 

The temperature-regulating mechanism is involuntary, and 
is effected almost wholly by reflex. 

The mechanism by means of which vasomotor and secretory 
functions are regulated by specific afferent nerves from skin sur- 
faces will be discussed elsewhere. 



206 PHYSIOLOGY I 

By covering the body with vaseline one may swim in water 
at 45° F. without experiencing discomfort from cold. (Carlson.) 

There is also some evaporation of moisture from the lungs, 
and this reduces body temperature. In some animals, the dog 
for example, the chief mechanism for the reduction of temperature 
is evaporation from the lungs and the cooling of the lungs by 
breathing; therefore the rapid panting of such animals when hot. 

A third way in which body heat is reduced is by the warming of 
inspired air by the lungs. All air when expired is warmed to, or 
nearly to, body temperature. If the temperature of inspired air 
is below that of body temperature, which is nearly always the 
case, there is some cooling of the lungs during each inspiration. 

There is also some loss of heat by means of the excreta, but 
the heat lost in this way is not great. 

Nerve Mechanism for Heat Regulation. — Much experi- 
mentation has been done, but as yet little is known regarding the 
mechanism by means of which the nervous system regulates body 
temperature. It may be that specific calorific nerves supply the 
visceral structures which regulate the oxidation processes in 
such a way as to effect thermogenesis; but while there is much 
physiological evidence in favor of this view, such specific nerves 
have never been demonstrated. 

That thermogenic or heat-regulating centers exist has been 
shown by operations on the brain and cord. The following facts 
have been demonstrated: Puncture or section of the medulla 
just behind the pons is followed by an increase in body temperature 
and an actual increase of body heat production, and cutting the 
cord in the lower cervical is followed by opposite results. There 
is also evidence to show that section of or injury to the cord in 
the upper dorsal region interferes with temperature regulation. 
Ott seems to have demonstrated a "heat center" in the corpus 
striatum, and other supposed centers which have something to 
do with heat production or body-temperature regulation have 
been located in the optic thalamus, in the septum lucidum, the 
cortex, mid brain, medulla and pons, but little is known other 
than that they seem to cause some thermic disturbance. 






Heat production 



GENERAL AND OSTEOPATHIC. 207 

From the evidence at hand we may conclude that there 

probably are centers in the brain and brain stem which inhibit 

the activity of centers lower in the cord. These centers in the 

cord are probably not specific heat centers, in that they send out 

specific heat fibers which regulate oxidation, but it is probable 

that these centers do have general control over such structures 

as the liver, etc., where heat energy is generated by oxidation. 

Howell states that "The unconscious regulation of the body 

temperature is effected chiefly through the following centers: 

f 1. The sweat centers and sweat nerves. 

,. . ,. ! 2. The vaso-constrictor center and the vaso- 

Heat dissipation i _. .. . . 

constrictor nerve fibers to the skin. 

^ 3. The respiratory center. 

1. The motor nerve centers and the motor 
nerve fibers to the skeletal muscles. 

2. The quantity and character of the food as 
determined by the appetite." 

Relation of Temperature to Environment. — The temper- 
ature of the surrounding medium is responsible to some extent 
for the temperature of the animal, its body heat production and 
loss of body heat. Homeothermous or warm-blooded animals 
maintain a rather constant temperature, the normal variations 
ranging within narrow limits. For man the possible variation is 
not more than 24° C, and this is uncommon. Starling states 
that in case of exposure individuals have recovered from a tempera- 
ture of 24° C. The highest temperature that can be borne by man 
varies with many conditions, but it may be said that 44° C. is the 
highest limit, and few cases ever recover from this temperature. 
That the temperature of warm-blooded animals, is largely inde- 
pendent of environment is shown by the fact that seals and other 
mammals living in frigid regions maintain a constant temperature 
equal to that of the human. 

In poikilothermous or the so-called cold-blooded animals, 
the temperature is variable and is determined largely by the 
temperature of the surrounding medium. In these animals changes 
in their environment cause changes in their internal temperature, 



208 physiology: 

and because the rate of chemical change in the body (metabolism) 
varies directly with the temperature, any reduced external temper- 
ature materially reduces the rate of oxidation and their heat- 
generating apparatus is reduced in activity. Their muscular 
and other body activities are also reduced, and the animal 
becomes inactive. Their heat-regulating mechanism is also very 
incomplete. 

Normal Temperature and Fever. — The normal tempera- 
ture of the human is about 37° C. or 98.6° F. when taken under 
the tongue. These figures are subject to variation and can only 
be taken as an average. 

Physiological Variation. — The temperature of most individ- 
uals shows a daily variation, being highest in the afternoon and 
lowest in the early morning, varying from .1° C. to .5° C. during 
this time. The cause of the low morning temperature is rest 
and decreased metabolism., and the activity during the day with 
increased metabolism is responsible for the increased afternoon 
temperature. In those who work during the night and sleep dur- 
ing the day this order is reversed. Active muscular exercise 
may increase the temperature to as much as 100° F., but it soon 
becomes normal after rest. Exposure to heat or cold may also 
cause slight variations. 

As stated above, the body is capable of only slight tempera- 
ture variations, and any marked increase or decrease from the 
normal is accompanied or followed by abnormal symptoms. An 
increase from 38° C. to 40° C. (100° to 104° F.) is always followed 
by symptoms of fever, and an increase above 40° C. nearly always 
results in loss of consciousness. No fixed point can be set as 
the " death mark, " but the maximum limit is seldom if ever higher 
than 44° C. 

Fever. — The term fever is applied to that abnormal condi- 
tion of the body characterized by an abnormal increase in body 
temperature, quickened pulse, thirst, abnormal metabolism, 
headache, etc., and is usually caused by some abnormal condition 
of metabolism or of the nervous system which disturbs the normal 
heat-production or dissipation. 



GENERAL AND OSTEOPATHIC. 209 

Fever is most commonly due to abnormal or foreign substances 
in the blood stream known as toxins. Toxins may result from: 
1, abnormal metabolism and the failure of the excretory organs 
to eliminate waste products, or they may be, 2, bacterial in origin. 
Toxins produce fever in one or more of the following ways: 1, by 
direct tissue stimulation, causing excessive metabolism beyond 
the power of elimination; 2, by disturbing the regulating mechan- 
ism of certain nerve centers which regulate body temperature; 
3, by directly stimulating the heart or its nerve centers, causing 
excessive functional activity of that organ, or by, 4, decreasing 
the functions of the organs of elimination. 

Osteopathic Significance. — The physiological principles 
underlying thermogenesis, or heat production, and thermolysis, 
or heat dissipation, should be well understood and it should be 
known that any factor which increases the former without a 
corresponding increase in the latter will surely result in an abnor- 
mal increase in the body temperature, or fever. 

It is known that the body contains within itself adjusting 
mechanisms for the regulation of temperature, and that normal 
structural relations will be followed by normal temperature ad- 
justment. It is known that there are certain so-called thermo- 
genic centers in the cord and brain, and that disturbance of these 
centers results in inability to maintain normal body temperature. 



SECTION V 



INTERNAL SECRETIONS 



CHAPTER XXIII. 
GENERAL CONSIDERATIONS. 

The functions of the skin as a receptive surface for afferent 
nerves which by their reflex association regulate the functions of 
internal structures to the external environment has been given, 
but there is another and in some respects a more effective way in 
which the various body activities are regulated, namely, by the 
secretions of the ductless glands. The name internal secretions 
has been given to the products of those glands which empty their 
secretions into the blood or lymph to differentiate this product 
from those secretions which are emptied into the alimentary canal 
or to the exterior through the skin and which are therefore properly 
termed external secretions. 

In some animals and plants, particularly the lower forms, this 
inter-relation of function, because of the total lack or inefficient 
system of nerves, is almost wholly regulated by chemical methods. 
Certain cells and cellular substances seem to exhibit specific 
chemical attractions in body fluids which serve important functions 
in the body. This specific quality, organo-chemical attraction, 
is known as chemotaxis, an example of which is the attraction 
of leucocytes to an inflamed area of the body or to bacteria. 
In lower forms of life, the protozoa and some metazoa, it may 
be said that the correlation of the body functions are almost 
altogether regulated by such a chemical mechanism. 

In the higher forms of life with the many intricate special 
functions and the widely differentiated structures for the perform- 
ance of such functions, the complicated, highly differentiated, 
and specific nerve connections by reflex activities do much to 
correlate the functions of various structures, yet the influence 
of internal secretions plays a very important part. It has been 

213 



214 physiology: 

shown how the liver and the pancreas are stimulated to activity 
by secretin, a duodenal hormone, and we may consider the action 
of all internal secretions as being produced in a similar way. Some 
authorities hold that every structure in the body produces a secre- 
tion which influences some other structure or structures in the 
performance of their normal functions. "In one sense we may 
say that every cell in the body is chemically connected with and 
dependent on all the other cells in the body. This interdepend- 
ence is a necessary consequence of the differentiation of function 
associated with increased complexity of the organism. " (Starling.) 
Bayliss and Starling by their work on hormones have perhaps 
done more to establish these physiological facts than any other 
workers in recent years. 

As evidence of how various tissue cells influence the functions 
of other structures Starling gives the following examples: 1. Food 
stuffs partially digested, secretogogues, etc., to all body tissues; 
2. Glycogen of the liver is supplied to all structures in need of 
glycogen as it is demanded; 3. Urea, produced by all tissues, 
when carried to the kidneys serves to excite excessive elimination 
by stimulating kidney cells ; C0 2 produced by tissues from internal 
respiration on its way to the lungs to be excreted excites the 
respiratory center, causing increased respiration. The adaptation 
of this mechanism to the demand of function, that of increased 
oxygenation of the blood by increasing respiration, can be readily 
seen; 5. Protection of other tissues by specific excretory function 
of certain structures, such as the function of the liver in taking 
ammonia from the alimentary contents and converting it into 
urea, thus protecting other structures from the injurious effects 
of ammonia if it should be circulated in the body fluid. 

Those substances termed chemical messengers or hormones, 
according to Starling must conform to certain requirements, as 
follows: 1. "They must not be antigens, i. e. their injection into 
the blood-stream must not evoke the production of an antibody. 
If this were the case, the hormone, on entering the blood-stream, 
would meet its antibody and would be unable to exert any effect 
on the appropriate reacting organ"; 2. " Since they must be 



GENERAL AND OSTEOPATHIC 215 

carried by the blood-stream to the reacting organ they must in 
most cases be susceptible to easy passage through the walls of 
blood-vessels if they are to excite a reaction within a fairly short 
space of time. This consideration would also tend to keep their 
molecular weight comparatively low. " 3. " As a rule the chemical 
messenger must excite a state of activity in response to a change 
in some other part of the body. When the primary change 
passes away, the action of the hormone should also disappear. 
On this account it is necessary that the hormone should either 
be susceptible of easy destruction, by oxidation or otherwise, 
in the fluids of the body, or be readily excreted, so that its action 
may not be continued indefinitely." (Human Physiology, Star- 
ling, 1912 ed.) 

Methods of Study. — Because these glands have no ducts 
and therefore their secretions cannot be collected for study as 
other secretions are studied, different methods must be employed. 
The methods most commonly used are given here: 

Extirpation. — By removing the structure from a normal 
animal by means of an aseptic surgical procedure and observing 
the abnormal symptoms which follow the extirpation, much may 
be learned concerning the function of such structures. Extirpa- 
tion may be either partial in which only a part of the structure 
is removed, or complete removal of the whole. 

Transplantation. — After extirpation of certain glands the 
symptoms may be relieved or in some cases seem to entirely dis- 
appear if similar glandular substance from another animal of the 
same species is replaced in the animal in such a way that a blood 
and nerve supply may enter it. It is sometimes necessary to 
make the transplantation before or at the same time the gland is 
removed, as, in case of the pancreas for example, death will often 
result before the transplanted glandular tissue has had time to 
become sufficiently functional to maintain life. It seems to make 
little difference with the glands of internal secretion as to what 
part of the body they are transplanted. Again, as in case of the 
pancreas, it is not necessary to transplant the whole gland to 
prevent the symptoms, as a very small portion will often suffice. 



216 physiology: 

Feeding of Extracts . — Extracts of the glandular structures 
are prepared by grinding the structure. In some cases the whole 
gland is fed and in others only certain parts of the gland, or its 
extracts, made by dissolving the ground gland in water, glycerine, 
or some other solvent. 

In some instances after extirpation, the feeding of these 
extracts materially relieves the symptoms which have resulted 
from the lack of the influence of the secretion of the extirpated 
gland. Therapeutically the feeding of such extracts has seemed 
to be of some value in the treatment of individuals suffering from 
undeveloped or atrophied glands. In many cases, however, this 
method of treatment is not followed by encouraging results. 

Intravenous injection of chemical extracts made from these 
glandular structures is also used to determine the immediate effects 
on the system. In many cases, as explained above, the action 
of such secretions necessarily extends over a limited space of 
time, and by this method such changes can be determined. In 
some cases other methods of study are employed, which will be 
described elsewhere. 



LUNG 




SCIATIC NERVE -± 



rmiiR mm upuard 



nth i?ib (douh a inuARD) 

LAST THOR NLRVt 
ITS CONHUWrt 

WITH LUIIMft tieXUi 



LIVER 



LUMBAR VESSELS 



LUMBAR NERVES 



LEFT INNOMINATE 
(rORUARD) 



-SUPERIOR GLUTEAL VESSEL 



CRiAT SCIATIC NERVE 



CONES hEUVI ISCHIADICI 
SCIATIC VESSEL 



FLMUR(DOMHARD) 



Plate XXIII. — This plate shows the kidneys, liver, and lungs and their bony relations. 
One rib is shown in lesion and the relation of the nerve to the lesioned rib is also shown. The 
dotted lines indicate the abnormal position of the innominates in relation to the sacrum. The 
right innominate is thrown forward, lengthening apparently the right leg. The left innominate, 
the reverse. Slipped innominates, from wrenches, sprains, falls, or twists, are found existing 
in patients in our everyday practice, and correction of these innominate lesion? results in the 
returning to a normal condition of the disturbed organs and tissues. 



CHAPTER XXIV. 
PHYSIOLOGY OF THE DUCTLESS GLANDS. 

It is now quite generally accepted that certain glandular 
structures such as the pituitary body, the thymus, the adrenals, 
the thyroids and parathyroids, the spleen, the chromaffin bodies, 
and possibly other structures function only as organs of internal 
secretion, while many other structures such as the pancreas, 
kidneys, liver, ovaries, testes, duodenum, stomach and lymph 
glands, which are known to have other functions, also produce 
important internal secretions. 

The Pancreas. — The external secretions of the pancreas 
have been given. The internal secretion, that which is emptied 
into the blood, is entirely a different substance, both as to origin 
and function. This secretion is probably produced by the 
islands of Langerhans of the pancreas. (See Series No. 4.) That 
there is an internal secretion of the pancreas which is altogether 
different from its external secretion, is clearly shown by the fol- 
lowing experimental findings: The duct of Wirsung may be so 
attached to the abdominal wall that the secretion is emptied to 
the exterior, the animal thus deriving no benefit from such secre- 
tion. In such animals if care be taken to not give too much fat 
in the diet the animal does not suffer. The same thing has been 
shown by ligating the pancreatic duct, plugging it with paraffin, 
etc. 

If, on the other hand, the pancreas is extirpated, severe symp- 
toms soon follow : Glycosuria, even on a strictly noncarbohydrate 
diet; an increased quantity of urine, polyuria; an increased quan- 
tity of urea ; abnormal hunger and thirst, and other less important 
symptoms. If partial extirpation be performed, leaving one- 
fourth or even a smaller part of the gland, the animal may live, 

217 



218 physiology: 

but the above symptoms with emaciation and death follow com- 
plete extirpation in a few weeks. Transplantation of a small 
part of pancreas in the abdominal cavity or beneath the skin 
of the suffering animal relieves the symptoms. 

In the human it is now almost as common to associate the 
disease diabetes mellitus with some abnormality of the pancreas 
as it is to associate mental affections with brain disorders. In 
diabetes the same symptoms, viz., glycosuria, polyuria, emacia- 
tion, etc., as are found to follow extirpation of the pancreas in other 
animals are common. In most cases of diabetes certain patho- 
logical changes may be found in the pancreas at autopsy. 

Osteopathic Significance. — We have shown in Series 
No. 4 that glycosuria, lasting for several months, may be 
produced in normal animals by artificial bony lesions of the 
mid-dorsal region of the spine. These animals showed other 
symptoms of diabetes, and while the percentage of sugar elimina- 
tion was not great in all cases it must be remembered that these 
animals were only kept for a few months and the diasese diabetes 
often requires years for development of the severe symptoms. 
Another explanation of the comparatively mild symptoms in these 
dogs is that they received the best of care during the period of 
lesion. 

In our series No. 12, we have shown that glycosuria can 
easily be produced in monkeys by artificial bony lesions, and 
that the correction of these lesions is followed by relief from the 
symptoms and an increase in the animal's weight. 

In the human it has been shown clinically by a great many 
osteopathic physicians that lesions of the mid and lower dorsal 
regions are found in diabetics, the correction of which is followed 
by relief from the symptoms. 

Pathological conditions of the pancreas following vertebral 
lesions have been found by McConnell and by McBeath in our 
series No. 12. 



GENERAL AND OSTEOPATHIC. 219 

THE ADRENAL BODIES. 

After complete extirpation of these glands in animals death 
results in a few days and, indeed, death may occur in a few hours. 
(12 to 24 hrs. — Starling.) The symptoms developing after extir- 
pation are muscular weakness, loss of vascular tone, and pros- 
tration. The symptoms in animals resemble those in Addison's 
disease, a disease of the human showing the above symptoms, 
together with the bronzing of the skin and vomiting, and is found 
to be associated with pathological conditions or atrophy of the 
adrenals 

The results of injection of the aqueous extracts are slowing 
of the heart-beat when the vagi are intact and an increase in blood 
pressure, but the increase in blood pressure is only of short dura- 
tion. A chemical substance, adrenalin, which can now be pre- 
pared synthetically, is known to be responsible for the increase 
in blood pressure. This substance is active in very small quanti- 
ties, "One four-hundredth of a milligramme per kilo body weight 
sufficing to evoke a definite rise of blood pressure." (Starling.) 
The rise of blood pressure is sudden and is accompanied by slow- 
ing of the heart-beat. After section of the vagi the injection of 
adrenalin is followed by a much greater increase in blood pressure. 
Starling states the results following the injection of the adrenalin 
as being practically the same as the functions of the spinal auto- 
nomics, viz., vaso-constriction, cardio-acceleration, pupillo-dilation, 
etc., but these effects are followed by paralysis of the vaso- 
constrictor fibers and therefore vaso-dilation follows the injection 
of over-doses. 

There is another function, that of neutralization of certain 
poisonous substances which seem to affect the neuro-muscular 
system. These detoxicatory substances produced by the adrenals 
were shown by Langlois, who found that the blood of frogs after 
the removal of the adrenals was toxic to other frogs. 

It seems that the activity of these glands can be increased 
by the stimulation of the spinal autonomics. If their secretion 
is so regulated it would seem highly probable that their functions 



220 physiology: 

might easily be influenced by spinal lesions. If, as we have clearly 
shown, the functions of the kidneys can be affected by spinal 
treatment, there is good reason to believe that these glands may 
also be similarly influenced. 

Adrenalin is frequently used in minor surgical operations as 
a hemostatic to prevent hemorrhage, but because its effects last 
only for a few minutes the injections must be frequently repeated. 
Osteopathic Considerations. — These structures are well 
supplied with blood, and probably no other structures receive 
a richer nerve supply from the spinal autonomics. Since we 
have shown that many other structures so supplied can be affected 
by spinal lesions and spinal treatment it is not unreasonable to 
suppose that these glands may be so affected. McConnell has 
found congestion of these glands in animals following bony lesions. 

CHROMOPHILE BODIES. 

It is known that other small bodies which resemble the medul- 
lary substances of the adrenals histologically and in staining 
characteristics are found in other parts of the body. In some 
animals many accessory suprarenal bodies are found, and in man 
such bodies are found in association with the autonomic ganglia. 
The secretion of these glands is probably very similar to, if not 
the same as, chromaffin or epinephrin produced by the medullary 
portion of the adrenals. Extracts when injected increase blood 
pressure. It is generally supposed that degeneration of these 
structures, like degeneration of the adrenals, is in some way asso- 
ciated with the condition known as Addison's disease. 

THE THYMUS GLAND. 

Results of Extirpation. — If the thymus gland be removed 
early in life there seems to be an overgrowth of the testes or ovaries, 
and the converse is also true, viz., that after castration or ovari- 
otomy in the young individual the thymus seems to grow larger. 
There seems to be, therefore, some " reciprocal relationship'' 



GENEKAL AND OSTEOPATHIC 221 

(Howell) between these structures. The fact that the thymus 
gland reaches its maximum of growth at or about the age of 
puberty and from that time on seems to atrophy and become 
functionless is further evidence of this relationship. 

Many other theories have been advanced concerning the 
functions of the thymus, as follows: 1. That this gland is asso- 
ciated in some way with growth and development during early 
life; 2. That it produces some secretion which influences the 
normal tone of the nervous system; 3. That it influences normal 
metabolism in some unknown way, such that thymectomy often 
results in malnutrition and death. 

The extract when injected seems to cause a decrease of blood 
pressure and an increase in heart beat. 

THE OVARIES AND TESTES. 

These organs are not usually classed with the ductless glands, 
as they have other essential functions, viz., in case of the ovaries, 
that of producing the female reproductive cells, the ova, and in 
case of the testes, that of producing the male reproductive cells, 
the spermatozoa; but it is known that they have other functions 
and that they produce useful internal secretions. 

The Testes — Effects of Castration. — Emasculation never 
causes death. Whether the operation is followed by diminished 
physical power is yet undetermined. There is experimental 
evidence to show that the internal secretions of the testes increase 
oxidation. 

Effects of Extracts. — Injection of extracts 1. increases 
both physical and mental activity; 2. increases systemic oxida- 
tion; (This is possibly the cause of the increased power to do 
work.) and 3. it increases the activity of the spinal centers and 
reduces the sensation of fatigue. 

The following functions may be attributed to the internal 
secretions of the testes: 1. Regulation of developmental changes 
before and after puberty; 2. Oxidation of certain food substances, 
which probably increases physical and mental energy; 3. They 



222 PHYSIOLOGY I 

may produce a detoxicatory substance which neutralizes certain 
body toxins. 

Some authorities, Lorand and others, state that if castration 
be performed before puberty the subjects never develop mascu- 
line characteristics and are less intelligent, and that the same 
is true of those whose testicles do not develop. There is also 
some reason to believe that those men whose testicles are well 
developed, other things being equal, are capable of greater physi-. 
cal and mental energy. 

The Ovaries — Effects of Extirpation. — Ovariotomy in 
animals is followed by 1. an increase in fat, 2. cessation of men- 
struation ("heat" in animals), and 3. a decrease in muscular 
and sometimes in mental vigor. In women the same changes 
occur after ovariotomy, and the premature menopause is often 
followed by distressing physical and mental symptoms which 
may be relieved in some cases by injection of extracts, feeding of 
extracts, or by grafting of ovarian tissue into the body. In dogs 
after ovariotomy the "heat" may be re-established by a trans- 
plantation of ovarian tissue under the skin, and the condition 
of menstruation can be produced in virgin animals by the injec- 
tion of ovarian extract made from the ovaries of a pregnant animal 
It seems, then, that we have an example of a nervous reflex func- 
tion caused by a chemical agent. 

The fact that women after the menopause usually get heavier 
and the fact that the same results follow after ovariotomy is evi- 
dence for the belief that the internal secretions of the ovaries 
prevent the laying on of fat, and in case of the ovaries and testes 
this is probably due to the lack of some agent whose purpose is 
the oxidation of fats. 

THE PITUITARY BODY. 

This structure consists of two parts, the anterior or glandular 
portion and the posterior or nerve portion. These two parts 
are histologically and embryologically different. The functions 
of this structure are yet very questionable, not because little 



GENERAL AND OSTEOPATHIC. 223 

work has been done to determine its function, but because of 
its location making successful experimentation, especially extir- 
pation, very difficult. 

Results of Extirpation. (Cushing's results.) — Section 
of the stalk seems to cause no effect, but removal of the glandular 
portion results in death in two days. These symptoms are that 
of a slow, chloral-like poisoning. Other workers claim that these 
results are of no significance because all animals died and that 
the death may have been due only to the operation. 

Extracts of the gland when injected into the normal animals 
(Shafer and Herring) produce vaso-dilation of the vessels of the 
kidneys and excessive secretion of urine. These extracts also 
cause pupillo-dilation and probably affect the spinal autonomics. 
Other viscera, the uterus, bladder, and so on, are also affected. 

The disease acromegaly, characterized by an overgrowth of 
bone tissue, was found by Marie to be associated with certain 
changes in the pituitary body. This excessive growth of the 
long bones due to the degeneration of the pituitary body is the 
cause of most of the cases of giantism commonly exhibited. 

The following functions have been ascribed to this structure 
through its internal secretions: 1. Regulation of secretion of 
the kidneys; 2. Regulation of the growth of bone tissue; 3. Some 
functional relationship exists between this structure and the 
thyroids, as this gland becomes more active after thyroidectomy; 
4. Its secretions play some part in carbohydrate metabolism, 
but it probably has just the opposite function of the internal 
secretions of the pancreas. The less the secretion of the pituitary 
body the greater the tolerance for carbohydrates. The above 
functions are probably associated with the posterior lobe, the 
secretions of which seem to be emptied chiefly into the cerebro- 
spinal fluid. 

THE PINEAL BODY. 

There is little known about this structure other than that it 
is probably a vestigial remnant of a primitive eye. In childhood 
it is glandular, but soon atrophies. 



224 physiology: 

Possible Functions. — It may have something to do with 
growth, but this is not probable. Extracts when injected are 
said to produce slight vaso-dilation. It may bear some relation 
to the development of the reproductive glands. 

THE THYROIDS AND PARATHYROIDS. 

These two structures are so closely related embryologically 
and anatomically that it is difficult to determine whether they 
have separate and independent functions. 

Results of Thyroidectomy. — Extirpation of these glands 
causes the most marked symptoms in carnivorous animals and 
less marked symptoms in the herbivora. Likewise after thy- 
roidectomy the greater disturbance results from the feeding of 
a meat diet. 

Complete thyroidectomy is usually followed by death in from 
one to four weeks. After the operation certain symptoms such 
as muscular tremors, convulsions, emaciation, and cachexia 
result. Atrophy of the thyroids in young individuals is accom- 
panied by lack of development both physically and mentally, 
which condition is known as cretinism. In the adult degeneration 
of the glands is followed by the disease known as myxedema, 
which is characterized by edema of the skin and mental disturb- 
ances. The deficient mentality in young individuals following 
atrophy or thyroidectomy is probably due to the lack of brain 
development rather than any lack of function of the internal 
secretions. 

Results of Extracts. — Extracts of these glands are prepared 
for feeding purposes in case of atrophy of the glands. These 
results are often unreliable because of the impurity of the extracts 
used. Symptoms developing after thyroidectomy have been 
relieved by the feeding of extracts to animals. The value of the 
feeding of extracts in cretinism is yet questionable, but in cases of 
myxedema good results have been obtained. 

Transplantation. — Grafting of thyroid tissue usually pre- 
vents the severe symptoms after thyroidectomy, and this method 




LAST THORACIC 



INFERIOR VENA CAVA 
LUMBAR PLEXUS 



H1N0HINA TE 

POUPART'J LIQ 

FEMORAL ARTERY 
FEMORAL VEIM 
ANT. CRURAL NERVE 



coccrx 



GREAT 5CI ATI CFIER.- 



Plate XXIV. — A lateral view of the bony framework is given in this figure showing the 
bony structures surrounding the liver and kidneys. The close relation of the nerve to the rib 
may be noted and it may be seen that lesions of the ribs could easily affect the nerves. The 
innominate is shown tilted backwards by a dotted line, raising the femur in the socket. The 
lines A, B, C, and D indicate the extent of the rotation of the innominate. When this condition 
exists we almost invariably find pelvic disturbances, as this bone assists in the formation of 
the pelvic basin. The correction of this subluxation tends greatly to restore to normal a varied 
number of disturbances which otherwise cannot be reached. See "Innominate Lesions'* in 
Part II of this book. 



GENERAL AND OSTEOPATHIC 225 

has been used with some success in practical surgery in cases of 
myxedema and cretinism. 

Secretions. — The substance of the thyroid upon chemical 
examination shows a greater iodin content than other body tissues, 
and it is supposed that iodin in some form is stored in these struc- 
tures and given to the blood as needed. The active chemical 
substance produced by the thyroids is known as thyroiodin. 

The Parathyroids. — It has been found that removal of the 
thyroids only, in certain animals is not followed by death or in 
some cases causes no severe symptoms, but if after thyroidectomy 
the parathyroids are removed, death results. 

The parathyroids probably produce something which neu- 
tralizes toxic substances formed elsewhere in the body. They 
are probably also associated in some way with the calcium salts 
of the body, as Macallum has shown. Whether they have differ- 
ent functions from the thyroids is not yet known, but that the 
thyroids and parathyroids are themselves functionally related is 
known. 

Hyperthyroidism. — Abnormal overgrowths, hypertrophy 
of the thyroids, or goitre, are of several kinds and are classified 
according to the nature of the growth and symptoms, which 
are probably a result of the secretions produced in excess. 

These, conditions are sometimes treated surgically by per- 
forming a partial thyroidectomy, after which the glands often 
continue to grow and the operation must be repeated. Because 
of the need of the secretion for body metabolism it is not advisable 
to perform a complete thyroidectomy. 

THE KIDNEYS. 

As a gland of internal secretion it has been shown that extracts 
of the kidney when injected into the blood stream of a living animal 
produce an increase in blood pressure. It is also claimed that 
the kidney produces an internal secretion which influences metabo- 
lism, and it possibly also produces a diuretic secretion by means 
of which it activates its own function. 



SECTION VI 



CONTRACTILE TISSUE 



CHAPTER XXV. 
PROPERTIES OF CONTRACTILE TISSUE. 

The contractile tissues of the body may be considered as 
muscle, ciliated epithelial cells, and those leucocytes which have 
the power of ameboid movement. The muscle tissue constitutes 
by far the greatest and most important of these. 

Ciliated Epithelium. — Ciliated epithelium is found on the 
mucous membranes of the following structures: 1. Air passages, 
e. g., the trachea, the larynx, the bronchi, and the nasal passages; 
2. the uterus, Fallopian tubes and epididymis; 3. the lachrymal 
duct and sac; 4. the Eustachian tubes; 5. the ventricles of the 
brain and spinal cord. 

The movement of the cilia of ciliated epithelium consists of 
a slow movement in one direction, which is effective in carrying 
foreign substances on its surface forward or towards the outlet. 
Following this there is a quick movement backward, which sepa- 
rates the free surface of the cilia from the object being moved. 
By this series of movements the cilia are able to gradually carry 
out foreign substances such as dust particles, etc., and in this 
way in many of the structures such as the mucous membranes of 
the air passages, this movement serves an essential protective 
function. In the Fallopian tubes the movement of the cilia per- 
forms another function, that of carrying the ova to the uterine 
cavity. The cilia of the ventricles of the brain and canal of the 
spinal cord probably have no function. These structures are 
the results of infoldings of the ectoderm, which at one stage in 
the animal's phylogenetic development represented the outer part 
or peripheral cell mass, and their cilia were then functional as 
motile structures. These cilia in the mammals represent only 
vestigial structures. 

229 



230 physiology: 

The motility of leucocytes has been discussed elsewhere. 
The purpose of such movements is readily apparent in that their 
power of motion enables them to move to places where they are 
needed for protection against invading bacteria, etc. Their 
power of ameboid movement enables them to penetrate the walls of 
the capillaries and thus come in direct contact with various tissue 
cells. White blood corpuscles, especially the motile leucocytes, 
may be considered the primitive cells of the body retained for the 
performance of certain functions common to the amoeba and 
similar cells. They have all of the primitive functions of proto- 
plasm — reproduction, motion, growth, etc., and in addition they 
seem to have developed exceptionally well the power of ingestion 
of foreign substances. This is an example of how a demand for 
a certain function has played a seemingly strange part, in that 
in this instance, instead of causing a specific differentiation it 
has caused the retention of original characteristics. 

This atavistic cell has, however, many important functions 
to perform and plays an important part in the body functions, 
just the same as the most highly differentiated and complex 
structures. 

PHYSIOLOGY OF MUSCLE. 

Muscle tissue is considered under three classes, viz., striated 
or voluntary muscle, smooth or non-striated muscle, and heart 
muscle, each kind differing in structure and function in certain 
respects. 

Striated Muscle. — Striated or skeletal muscle constitutes 
that which is concerned with the voluntary movements of the 
body. The fibers consists of single, large, multinuclear cells 
and lie in bundles which are known as fasciculi. Each fiber is 
inclosed in an elastic membranous sheath termed the sarcolemma. 
The sheath contains the semi-fluid muscle plasma and fibrils. 
The fibers are long, thread-like structures, extend longitudinally 
through the cell, and are surrounded by the sarcoplasm. 
These fibrils are striated transversely, which gives to the cell its 
name of striated muscle. The fibrils lie in groups known as 



GENERAL AND OSTEOPATHIC. 231 

sarcostyles, which float in the sarcoplasm. These fibrils are 
generally considered to be the contractile elements of the cell. 

Heart Muscle. — This type of muscle is found in the heart 
and in the diaphragm. It differs from striated muscle in that 
the cell contains a greater amount of sarcoplasm, which is granular 
and in some respects more nearly resembles undifferentiated 
protoplasm. Heart muscle differs from striated muscle in that 
the fiber is mononuclear, the nucleus being located near the middle 
of the cell; the cell is smaller, it has no sarcolemma, the cells are 
branching and irregularly arranged, and the transverse striations 
are not so distinct as in the striated fibers. Heart muscle differs 
from striated muscle functionally in that the rate of contraction 
is slower, its contractions are rhythmical, it is considered non r 
fatigable, it is said to contract equally, regardless of the strength 
of the stimulus, and is to some extent under control of the will 
power. 

Smooth Muscle. — Smooth or involuntary muscle is found 
in the walls of the following viscera: It constitutes the muscula- 
ture of the walls of the alimentary canal from the mid or upper 
portion of the oesophagus to the internal sphincter ani; it forms 
the musculature of the uterus and Fallopian tubes, the urinary 
bladder, the gall bladder and duct, the trachea and bronchi, the 
ducts of all glands, the seminal vesicles, the blood vessels and 
lymphatics, the intrinsic muscles of the eye (iris and ciliary muscles) , 
the tunica dartos and the muscles of the skin. 

The fiber is mononuclar, the nucleus lying near the center, 
and is striated longitudinally. It differs from the other kinds of 
muscle in the nature and structure of the cells, as stated, and 
differs functionally in that the rate of contraction is much slower 
than in either of the other kinds; the contractions are progressive, 
but not necessarily rythmical; like heart muscle it is practically 
nonf atigable because the contractions occur slowly, and like striated 
muscle the extent of contraction varies directly with the strength 
of the stimulus. 

Blood and Nerve Supply. — The muscle fiber is supplied 
with blood by a meshwork of small capillaries about each fiber. 



232 PHYSIOLOGY : 

Smooth muscle is supplied by nerve fibers from the autonomic 
system only. Heart muscle is supplied by nerve fibers from the 
autonomic system and also by fibers from the central nervous 
system. Striated muscle is supplied by nerve fibers from the 
central nervous system only. The axis cylinder of the nerve 
fiber terminates in a motor end-plate which transmits the im- 
pulse to the muscle fiber, and the primitive sheath of the nerve 
fiber becomes continuous with the sarcolemma. 

GENERAL PROPERTIES OF MUSCLE. 

Elasticity and Extensibility. — All muscle tissue is normally 
elastic and extensible. The muscle fiber may be made to extend 
by the application stress, but unlike non-living extensible sub- 
stances the strain or amount of extension is not proportional to 
the stress or distorting force except within certain limits. If 
weight, for example, be applied to rubber the extension continues 
in proportion to the increased weight added. This is true of 
muscle tissue for a medium amount of extension, but, if continued, 
soon the limit of elasticity is reached and the muscle loses its 
power to retract. (Weber's paradox.) 

Muscle tissue is normally in a state of constant tension, which 
is variable, depending upon the kind of muscle, the physiological 
state of the muscle, and the nature of the blood and nerve supply. 
If the normal amount of stimuli to the muscle fiber by way of the 
nerve fiber is decreased, the tension or tone of the muscle fiber is 
diminished, and if the amount of stimuli is increased the tension 
is increased. That muscle tissue is in a state of constant tension 
may easily be demonstrated by the shortening which immediately 
occurs when the tendon of a muscle is cut in a living animal. 

The purpose of this constant tension is chiefly for the purpose 
of regulating normal voluntary movements. If, for example, a 
stimulus were sent quickly to a set of muscles with the intent of 
performing some regulated movement and the muscles stimulated 
were without tension, the quick contraction would result in a 
jerk instead of a regulated movement- There are, of course, 



GENERAL AND OSTEOPATHIC. 233 

many other reasons why a certain amount of constant muscular 
tone is of value to the normal functions of the muscle, such for 
example as the dangers of over-strain, etc. 

Irritability. — The cause of muscular contraction is ulti- 
mately the stimulus sent to the muscle by way of its efferent 
nerve fiber. Irritability may be defined as that property of 
muscle or other tissue by virtue of which it may be made to func- 
tionate as a result of stimulation, and the term " stimulus" is 
definable only in terms of irritability. Stimulus may therefore 
be defined as any influence which has the power of causing irri- 
table tissue to functionate. 

As evidence that nerve stimulus is the cause of normal tone 
and contractility in muscle it may be stated that, if the nerve 
to the muscle be severed the tone of the muscle is lost, paralysis 
follows, and the muscle tissue degenerates. On the other hand, 
if the end of the nerve leading to the muscle (peripheral end) be 
stimulated artificially, the tone of the muscle fibers is increased 
and contraction of the muscles quickly follows. The nerve is 
essential to normal muscle contraction by applying stimulus 
directly to the latter, but muscle to which the nerve has been 
sectioned cannot be made to contract voluntarily, and, if the 
nerve does not soon regenerate, atrophy in this case may be due 
to one or the other or both of two causes: First the atrophy 
of disuse, and second, the atrophy which results from the inability 
of the muscle to regulate its nutrition. This latter, the so-called 
trophic influence of the nerve, is not well understood. Whether 
the nerve actually changes in the muscle or whether, by affecting 
the blood supply or in some other way the nutrition is affected, 
is not known, but that the nerve is essential to normal nutrition 
and growth of the muscle has been positively established. 

Effect of Curare. — Curare is a vegetable extract prepared 
from certain members of the Strychnos family and used by South 
American natives as an arrow poison. Alkaloids of this drug 
when injected into living animals destroy the action of the motor 
nerves to muscles by affecting the end-plates. The experiment 
is usually carried out by injection of solutions of the drug beneath 



234 PHYSIOLOGY : 

the skin of a frog. Direct stimulation now applied to the muscles 
of the curarized frog produces contraction of the muscles stimu- 
lated, but stimulation of the efferent nerve to the muscle produces 
no effect. This shows that the nerve is not essential to muscle 
contraction. If only a small amount of curare be used the effect 
soon passes off and the muscle may again be made to contract 
by stimulation of the motor nerve. 

Artificial Stimulation, — For the purpose of studying the 
functions of various nerves and their power of regulation of various 
structures certain methods of stimulation artificially have been 
employed. 

1. Mechanical Stimulation. — Nerves may be stimulated 
mechanically by applying direct pressure to the exposed nerve 
trunk. Only a slight pressure is necessary to produce variations 
in nerve activity. If quick pressure be applied to a nerve trunk, 
such as pinching or by gently pulling or jerking, the effect is 
stimulation and an increase in the functional activity of the struc- 
ture or structures supplied, if it be the peripheral end of the nerve. 
If such mechanical stimulation be applied to the central end of a 
mixed or sensory nerve the result is stimulation of the centers 
and is followed by reflex effects. If steady pressure be applied 
to a nerve trunk by pressure or by ligature the result is at first 
stimulation, but this is followed by inhibition or a decreased amount 
of stimulation, which in turn is followed by decreased activity 
of the structures supplied. Structural lesions such as contrac- 
tured muscles, subluxated bones, or visceral lesions may be effect- 
ive in causing such effects. This, however, is not the only explan- 
ation of the effects of osteopathic lesions. 

2. Thermal Stimulation. — Nerve trunks and muscle tissue 
may be stimulated by the application of cold or heat to the struc- 
ture. Only slight changes in temperature are necessary to pro- 
duce variations in nerve stimulation. In the stimulation of 
nerve trunks by this method some hot or cold metallic substance 
is usually used, applying it directly to the nerve. Temperature 
stimulation may also be effected by dipping the nerve into cold 



GENERAL AND OSTEOPATHIC. 235 

or. hot water or by the application of hot or cold packs to the 
various regions of the body. 

3.- Chemical Stimulation.- — By the application of various 
chemical substances such as weak acids and alkalies, strong- 
salt solutions, etc., to nerve trunks, stimulation may be effected. 
If the chemical stimulant be left in contact with the nerve trunk 
for a length of time, or if strong solutions be .applied, the result 
is inhibition. An example of this is the effect of C0 2 on the 
conductivity of nerve fibers. If CO2 be passed around nerve 
trunks or cell centers they soon lose the power of conductivity. 
Oxygen, on the other hand, increases conductivity. 

4. Electrical Stimulation. — Electrical stimulation applied 
to nerve trunks or to various other structures by means of plati- 
num electrodes from an induction coil (induced or faradic current) 
is most generally used for artificial stimulation. The advantages 
are that the strength of the stimulus can be regulated, it can be 
applied more directly to the part selected, usually affects all 
fibers of the nerve trunk equally, thus giving co-ordinated con- 
tractions, and, if the current is kept weak there is less danger 
of injuring the nerve than by other methods. 



CHAPTER XXVI. 
MUSCULAR CONTRACTION. 

The Simple Contraction.— The shortening of a muscle 
which results from the effect of a single stimulus is known as 
a simple muscular contraction. The nature of such contrac- 
tions is studied best by using the gastrocnemius of a frog in a 
moist-chamber apparatus. By this means, either by stimulation 
of the muscle directly or by stimulating the nerve to the muscle, 
the record tracing of the curve of contraction (contraction fol- 
lowed by relaxation) may be made on the smoked paper of a 
kymograph for the study of its component parts. 

Contraction Time. — The length of time necessary for 
the shortening of muscle varies with different species of animals 
and with differ et muscles in the same individual animal. The 
following table from Howell gives a general idea of such varia- 
tions : 

Duration of a Simple Muscular Contraction (Howell). 

Insect . 003 second 

Rabbit (Marey) 0.070 " 

Frog 0.100 " 

Terrapin 1.000 " 

The series may be continued by the figures obtained from 

the plain muscle, thus: 

The involuntary muscle (mammal) 10 . 00 

Foot muscle of slug (ariolimax) 20 . 00 

A little study of the significance of this table will reveal 
an example of the result of structural adaptation to the demand 
of function. The purpose of the quick movements of the insect 
muscle may be explained in the demand of such movements that 
the insect may escape its enemies. The same is true for the 
rabbit muscle, as this animal depends upon its speed for purposes 
of protection while the terrapin has another and much more 

236 



GENERAL AND OSTEOPATHIC. 237 

effective method of protection and there seems to be no real need 
of quickness of muscular activity. 

Plain muscle requires from ten to twenty seconds for con- 
traction, and here again it may be seen that there is a greater 
demand for slow, regulated movements (peristalsis of the gut, 
for example) than for quick movements. 

In the contraction curve it may be seen that the muscle does 
not begin to contract at the very instant of the application of 
the stimulus, but that the shortening actually begins a short 
time after the stimulus is applied. This period of time which 
elapses between the time of the application of the stimulus and 
the beginning of contraction is known as the " latent period." 
In frog muscle this is equal to about .01 second and is probably 
due to inefficiency of the apparatus, or elasticity of muscle tissue. 
Some time is necessary for the chemical changes which initiate 
contraction, and time is actually necessary for the beginning of 
the shortening of the muscle after the chemical changes have 
occurred. 

The contraction curve is divided into two parts, called phases. 
They are the phase of shortening, about .04 second, and the phase 
of relaxation, which is about .05, making the total time of the 
contraction wave about .09 second. 

The Latent Period. — The muscle does not begin to shorten 
instantly after the application of the stimulus to the nerve of a 
muscle, but a short period of time always elapses, about 
.01 second, which, correcting for errors of the apparatus used, may 
be greatly reduced. This period of latency is probably due for 
the most part to the time required for the occurrence of the chemi- 
cal changes necessary for the production of the energy. Other 
factors, such as elasticity of the muscle, inertia of the muscle, 
and load to be lifted, also tend to retard contraction. 

The period of latency is not constant, but varies for different 
muscles and for the same muscle under different conditions, such 
as temperature, tone, condition of fatigue, etc. 

Conditions Affecting Muscular Contraction. — There 
are various conditions which may influence the nature of mus- 
cular contractions: 



238 physiology: 

1. Temperature variations affect muscular contractions 
in a peculiar way. In case of the frog the muscle loses its irrita- 
bility at about 0° C. From this temperature the irritability 
increases up to about 9° C. and decreases as the temperature is 
increased up to about 17° C. From this temperature the irri- 
tability increases again as the temperature is increased until a 
temperature of about 30° C. is reached. Beyond this the irrita- 
bility decreases up to about 37° C, when the contraction ceases. 
In most striated muscle there is a certain optimum temperature 
for muscle contraction, which is about that of the normal body 
temperature of the animal and a maximum temperature above 
which muscle will no longer function. The maximum tempera- 
ture for muscles of most mammals is from 43° to 45° C. Proto- 
plasm cannot withstand high temperatures and, generally speaking, 
no tissue can maintain its functional activity above 45° C. 

The functional activity of all tissues seems to increase as the 
temperature increases up to a certain limit. For homeothermous 
animals this limit is from 40° C. to 45° C. 

2. Muscular contraction varies also with the strength of 
the stimulus applied. If the stimulation apparatus, an induction 
coil, be so arranged that a light stimulus may be discharged to 
a muscle-nerve preparation and the result recorded on the smoked 
paper of a kymograph and, after allowing a period for rest, a 
stronger stimulus is applied the increased amount of shortening 
may be measured. It may thus be shown that, other conditions 
being equal, the amount of shortening (contraction) varies directly 
with the strength of the stimulus. 

Contracture of Muscle Tissue. — Contracture may be 
denned as a condition of maintained contraction or as a condition 
of retarded relaxation. The muscle becomes very rigid and the 
power of relaxation is temporarily lost. This condition must 
not be confused with the simple muscular contraction. 

Causes of Contracture. — 1. If a muscle be caused to func- 
tion excessively either by the application of artificial stimuli 
rapidly repeated or by excessive work from normal stimulation, 
such as a long continued lifting of a load, which in either case may 



GENEKAL AND OSTEOPATHIC. 239 

cause fatigue, the condition of contracture may result; 2. Quickly 
applied stimuli are often a cause of contracture. This may be 
shown experimentally by suddenly throwing a strong electrical 
stimulus into the nerve to a muscle, as in a muscle-nerve prepara- 
tion. The same condition sometimes occurs in athletes who try 
to make an unusually sudden and vigorous movement; thus the 
need of the so-called " warming-up exercises" before the race. 
If the muscles are gradually exercised they become much more 
receptive to the effects of strong stimuli. The occurrence of 
" cramps" may be explained in this way, the excessive stimulation 
of cold water or, as explained above, the unusual attempt to per- 
form some muscular movement may serve to overstimulate the 
muscle; 3. Contracture as a result of rapidly repeated stimuli 
may be demonstrated by sending a series of stimuli into a muscle- 
nerve preparation. The apparatus must be so arranged as to 
electrically stimulate the muscle very rapidly. The condition 
of contracture which results may last for several minutes. 

Tetanic or Compound Contractions. — Tetanus of muscle 
may be defined as a condition of maintained contraction resulting 
from a series of rapidly applied and continued stimuli. It may 
be thought of as a long lasting condition of contracture. The 
various conditions mentioned above as cause of contracture may 
also be causes of tetanus. The application of rapidly repeated 
stimuli in such a way as to cause the muscle to begin a second 
contraction before the effects of the first is lost, thus allowing 
no time for relaxation, explains the mechanism of tetanus. 

If the stimuli are not rapidly applied, but continuously re- 
peated so the muscle slightly relaxes between the stimulations, 
complete fatigue will not occur for a longer time and, if the stimu- 
lation be stopped, the muscle quickly recovers. This condition 
is known as incomplete tetanus. 

If the stimuli be more rapidly repeated and continuously 
applied the muscle shortens and remains shortened with no relaxa- 
tions between the application of the stimuli. This condition is 
known as complete tetanus. A continuous repeated stimulation 
of 300 per second is necessary for the production of a condition 



240 physiology: 

of complete tetanus. The rate of stimulation for complete tetanus 
varies for different muscles and other conditions, such as tempera- 
ture, etc. 

In complete tetanus of a muscle, the tracing of which shows 
no variation, it may be shown that each separate stimulus produces 
its own independent effect and that chemical changes occur for 
each contraction. The discontinuous nature of the tetanus may 
thus be shown. 

Pathological Tetanus. — The disease tetanus, in animals 
and human individuals commonly known as lockjaw, is caused 
by one of the toxins of B. tetani, tetanospasmin. This toxic 
substance when injected into an animal produces symptoms of 
tetanus (contracture of muscles) in from twelve hours to three 
days, the time varying with the dose used. The musculature 
involved becomes tense and occasionally spasmodic contractions 
occur until the disease progresses to the stage where complete 
tetanus obtains. The symptoms in tetanus are brought about 
by an increase in the reflex activity effecting an increased excita- 
tion of the motor nerve cells of the spinal cord, medulla, and pons. 
The muscles first involved are those nearest the point of inocula- 
tion in most cases, the condition spreading to other groups of 
muscles until before death the entire body musculature may be 
affected. 

Summation. — A condition known as summation of stimuli 
may be effected by causing a second stimulus to pass into the 
muscle before the effect of a first stimulus is lost. If, for example, 
the muscle be stimulated a second time at the end of the first 
phase of a simple muscular contraction a second and higher rise 
in the muscle curve will result. 

The amplitude of the second curve varies with (1) the strength 
of the second stimulus., the amount of the contraction increasing 
as the strength of the stimulus is increased; (2) the amplitude of 
the second contraction also varies directly as the interval between 
contractions and (3) varies inversely as the load on the muscle. 

The above phenomena show that the muscle ordinarily does 
not contract". to it's maximum of capacity and that a second or 



GENERAL AND OSTEOPATHIC. 241 

continued series of contractions is possible and may be regulated 
by the amount of stimulus applied. 

In the mechanism of voluntary muscle contractions, to be 
discussed later, the increased power of shortening due to increased 
stimulation explains the regular and continuous shortening of 
the muscles in voluntary movements. 

Treppe. — If in the muscle-nerve preparation a series of 
slowly repeated stimuli be applied to a muscle and the amount 
of shortening be recorded on a kymograph, it will be noted that 
each stimulus is followed by an increased amount of shortening. 
This is the so-called staircase effect or " treppe." It is due to 
the increased irritability of muscle after a series of moderate 
stimuli. The result shows the increased functional activity 
caused by a gradually increasing susceptibility of muscle tissue to 
nerve stimulus. 

The Contraction Wave. — If in case of an isolated or curar- 
ized muscle a stimulus be applied directly to one end of a sus- 
pended muscle, a wave of contraction may be seen to move over 
the muscle from the point of the application of the stimulus. 
The wave so produced affects the fibers, causing contraction in 
them as it progresses through the muscle. The velocity of the 
contraction wave in human muscle is from ten to thirteen meters 
per second and from three to four meters per second in frog muscle. 

This kind of contraction does not occur in normal physio- 
logically active muscle. There is a special provision for the equal 
stimulation of all muscle fibers at one time. The motor end 
plate being situated at or near the central portion of the muscle 
fiber provides for the equal stimulation of all fibers, and thus 
the contraction wave is prevented. Contractions occurring in 
muscle from normal nerve stimulation are a result of the effects 
of a generally applied stimulus to all fibers, they contracting in 
unison and in the same phase. 

Idiomuscular Contraction. — Idiomuscular contraction is 
the local contraction due to the application of a local stimulus. 
It may be demonstrated in dying muscle or pathological muscle by 
stroking or otherwise locally stimulating the part. 



242 physiology: 

Nature of Voluntary Contractions. — By comparing the 
time of voluntary contractions with the time of a simple muscular 
contraction it will readily be seen that the latter is far too short 
to explain the nature of most voluntary movements. Voluntary 
movements are therefore most likely tetanic in nature and are 
caused by a gradually increasing amount of stimulus supplied by 
the efferent or motor nerve to the muscle. 

The neuro-muscular mechanism consists of the fol- 
lowing various parts: 1. The upper motor (pyramidal) neuron 
extending from the higher or cortical centers to the anterior 
(motor) horn cells of the various parts of the cord. Its function 
is association and regulation of the functions of the motor cells 
of the cord; 2. The lower motor (spinal) neuron extends from 
the cord to the muscle and supplies nerve energy for the initiation 
of muscular contraction. These two fibers constitute the path- 
way by means of which the stimulus passes from the cortical and 
cord centers to the active muscle. 

An average of about ten impulses per second are sent to 
muscle by way of the motor nerve for purpose of causing normal 
muscular contraction, which is continued during the entire time 
the muscle is thus functioning. If at any time during the con- 
traction the action needs to be increased the amount of stimulus 
is correspondingly increased. The normal muscular contraction 
therefore consists of a series of single contractions which result 
in the gradually increasing and regulated movements, and during 
this period the muscle is in a state of controllable tetanus. 

During the period of contraction if a stethoscope be applied 
a sound (muscle tone) may be heard, which is thought to be pro- 
duced by the contracting fibers. These tones vary from thirty- 
five to forty per second. This rate is generally thought to be 
too high and that the rate of vibration is much lower than this. 
Since the human ear cannot detect sound vibrations lower than 
forty per second, it is likely that the sounds heard are overtones 
of the lower and inaudible tones. 



CHAPTER XXVII. 
NORMAL FUNCTIONS OF MUSCLE TISSUE. 

Methods of Study of Voluntary Contractions. — Various 
methods have been employed for the study of voluntary contrac- 
tions in animals and in man, some of which will be given. 

The Ergograph. — The ergograph is an instrument so con- 
structed that the forearm is held firmly fixed in an arm rest while 
the middle finger is gripped into a stirrup attached to a weight- 




Fig. 23. — The Ergograph. 

lifting device. By this means the functional powers of the flexor 
sublimus digitorum muscle may be studied. A tracing pointer 
from the apparatus is extended to a kymograph for recording 
the results. 

The conditions necessary for the study of muscular work 
by this means are: (1) The other parts of the arm must be held 
immovable and only one muscle or a single group of muscles 

243 



244 physiology: 

allowed to act in lifting the load; 2. The weight must be known 
and adjusted to the relative lifting power of the muscle; 3. The 
weight must be lifted through a definite distance at each contrac- 
tion, that the total amount of work done may be calculated; 
4. The contractions must be effected at regular intervals, thus 
not allowing long periods of time for rest. Under these conditions 
much may be learned concerning the functional activities of 
muscle, butthere are yet many sources of error. After the muscle 
has undergone complete fatigue from the lifting of a heavy weight 
it may still be able to lift a lighter load. The total amount of 
possible work of a muscle cannot, therefore, be accurately deter- 
mined by this method. 

Muscular fatigue may well be studied by this method and 
the results of such an experimental study furnishes some inter- 
esting information, as follows: 1. That if sufficient length of time 
be allowed for rest between contractions fatigue does not result. 
This fact would tend to confirm the theory that while functioning 
the muscle actually uses energy which is quickly restored if the 
muscle be allowed to rest. This restoration of energy is effected 
chiefly by the carbohydrates of the blood and the glycogen content 
of the muscle. If sufficient load is used and the muscle is made 
to contract without allowing periods of rest, fatigue results. The 
length of time necessary for complete fatigue varies inversely 
with the load and directly with the length of time allowed between 
contractions. After complete fatigue a period of about two hours 
is required for restoration of the muscle. After complete fatigue, 
any attempt to contract the muscle prolongs the period of restora- 
tion to functional activity. These facts show that fatigue and 
over-stimulation of muscle is injurious. 

There are many other factors which affect functional 
activity of muscle, as may be shown by the ergograph. It may 
be shown that anything which injures the general nutrition and 
health, such as the loss of sleep, lack of food, anemia, etc., reduces 
muscular power. Mental activity also reduces muscular power 
and this fact seems to show that surely a definite amount of body 
energy, which may be called nerve force, is used in mental activity. 



GENERAL AND OSTEOPATHIC. 245 

Anything which improves the general circulation, such as 
massage, increases muscular energy; and anything which inter- 
feres with the circulation to a muscle or group of muscles reduces 
the muscular power. Muscular energy may be increased by the 
feeding of foods which are readily absorbed, such as the soluble 
sugars. The use of one set of muscles decreases the muscular 
power of all. This may be shown by doing some kind of work 
with the musculature of another part of the body, while one set 
of muscles is doing work on the ergograph. The absolute power 
and the length of time of fatigue are both reduced. This and 
other phenomena described above show how the various parts 
of the body machine depend upon a common supply of energy 
and how a usage of this common supply reduces the amount to 
be distributed. 

During the period of work on the ergograph the operator 
experiences certain feelings or sensations which make it possible 
for him to realize the conditions of his acting muscles. At the 
outset of the experiment the load seems light and his muscles 
respond with little effort, but as the work continues a point is 
reached when he feels that the load is getting heavier and that 
his muscles are not responding to his efforts. Then soon he 
begins to feel a slight sense of pain upon contraction, which is a 
sensation transmitted from the tendons and muscles by way of 
the afferent fibers from the functioning parts. This condition 
is known as the sense of fatigue. 

Muscle Tonus. — Muscle tonus is a condition of slight but 
continuous contraction of the muscle fibers as a result of a supply 
of a comparatively slight amount of nerve stimulus. It may be 
considered a condition of subdued tetanus and is just sufficient 
to keep the muscle fibers on slight tension. The stimulus of 
the efferent nerves which maintains muscle tone is in turn due to 
a slight stimulus sent into the cord and brain centers by way of 
the afferent nerves from the sensory surfaces. By this mechanism 
the motor centers are kept active, and reflexly the muscles are 
constantly receiving sufficient nerve stimulus to maintain their 
normal tension or tonus. 



246 physiology: 

As evidence of this condition of muscular tonus it may be 
shown that the condition is lost in muscle to which the nerve 
supply has been sectioned, or by degeneration of nerve tissue or 
nerve centers from the effects of the various nervous diseases. 

By sectioning the posterior roots it may be shown that these 
effects are controlled by reflex mechanism, as there is a corre- 
sponding loss of tonus to the muscles innervated from the segments 
to which the afferent supply has been sectioned. Since it has 
been shown that muscle tonus is due to the activity of both the 
afferent and efferent fibers it is equally true that muscle tonus 
is dependent upon the cell centers, their association fibers and the 
condition of the synapse, and, as will be pointed out later, the 
function of nerve centers depends upon conditions about and 
within the cord, such as blood supply, venous and arterial drain- 
age, and normal movements of the vertebral segments upon which 
these factors depend. Osteopathically, then, the conditions 
determining muscular tonus are immediately apparent. 

Physiological Significance of Tonus, — It is not difficult 
to see the value of a normal condition of muscular tonus to active 
muscle. The condition allows the ready response to stronger 
stimuli, thus rendering possible the regular and controllable 
and voluntary movements. The stimuli to the muscle- also assist 
in some way in maintaining the normal nutrition of the muscle. 
It has not been demonstrated that the motor nerve has any spe- 
cific trophic function to the muscles, but it certainly does in some 
way regulate the nutrition of the muscle. It may be that the 
maintenance of normal functional activity, which function is 
regulated by the nerve, determines the metabolic processes of 
the cells and in this way the motor nerve indirectly performs its 
trophic function. 

The regulation of the temperature of the muscle and the 
skin surfaces depends upon this regular supply of nerve impulses 
to the structures. This temperature-regulating mechanism in 
turn determines the nature of the afferent impulses sent into the 
nerve centers, so it may readily be seen that the two functions are 
intimately dependent upon each other. The cutaneous trophism 



GENERAL AND OSTEOPATHIC. 247 

determining the afferent stimuli to the nerve centers and the 
activity of the centers determine the efferent stimuli to the struc- 
tures. The activity of the centers therefore would seem to be 
the most important of the three factors, and as long as the centers 
are functioning properly the adaptation of the other parts to 
environmental and other conditions may be expected to follow. 
It is known that the nerve centers may be affected by osteopathic 
lesions and the functional activities of such centers may be nor- 
malized by corrective manipulations. 



CHAPTER XXVIII. 
CHEMICAL PROPERTIES OF MUSCLE. 

Muscle plasma, which constitutes nearly all of the cytoplasm 
within the sheath of the fiber, as shown by Kuhne is capable of 
undergoing coagulative changes when injury to the cell results, 

This material clots and forms serum very similar to that 
formed in the process of blood coagulation. This clotting is 
thought to be the cause of the production of rigor. 

There are two fairly well-known muscle proteins, myosin, 
a globulin, which in the process of clotting forms myosin fibrin; 
and myogen, an albumin, which in the process of clotting forms 
myogen fibrin, and these proteins are also thought to take part 
in the process of rigor. 

Water constitutes about 75% of muscle. The quantity 
varies inversely with the age of the animal, young individuals 
having the greatest amount. It is also said to vary with different 
muscles of the same individual, but the variation is not great. 

The water content is increased in tetanized muscle. Activity 
therefore seems to increase the water content. 

Several other substances to be discussed more in detail 
later, such as sugar, glycogen, etc., are found in small amounts. 

The following table, taken from Stewart, showing the compo- 
sition of dead striated mammalian muscle, will serve to give the 
general composition. Variations from this may be found in dif- 
ferent species and in different muscles even of the same individual : 

Water 75 per cent 

Proteins 20 per cent 

Fats, lecithin, and cholesterin 2 per cent 

( kreatin (0.2 to 0.4) ) ] 

Nitrogenous metabolites j xanthin > purin bodies j 

( hypoxanthin, etc. ) I 2 Der cent 

Carbohydrates (glycogen, dextrose and maltose) F 

Lactic acid 

Inosit 

248 



GENERAL AND OSTEOPATHIC. 249 

Inorganic salts such as the carbohydrates, phosphates, chlo- 
rides and sulphates of sodium, potassium, calcium, magnesium, 
iron, and possibly some other metals are found in muscle, but the 
total quantity is less than one per cent. 

Muscular Rigor. — Muscular rigor is a condition of muscle 
rigidity and contraction of muscle which is found to occur after 
death and is commonly known as rigor mortis. The changes 
known to occur are rigidity, shortening, an acid reaction results, 
there is a loss of irritability, and the proteins solidify, and the 
semi-fluid muscle plasma of the living state is reduced to a firm 
mass. 

This condition passes away in from one to six days after 
death, and the muscles again become soft as before. In cold- 
blooded animals rigor occurs much more slowly. Another form 
of rigor, caused by quickly increasing the temperature of muscle, 
rigor caloris, may be considered as similar to, if not the same 
as, rigor mortis. It is supposed that the increase of temperature 
causes death of the tissues by effecting certain chemical changes 
and that the rigidity, etc., are due to the coagulative changes, the 
same as in rigor mortis. 

MUSCLE ENERGY AND WORK. 

The source of energy for muscular contraction is the breaking- 
down of the complex carbohydrate compounds and the reduction 
of such complex molecules to simpler molecules. By this process 
energy is liberated. This is the energy of muscular work. The 
exact nature of these chemical changes is not well understood, 
but they are for the most part oxidation processes liberating carbon 
dioxide and water, and are exothermic in nature. Heat energy 
is therefore produced. 

It has been positively demonstrated that the source of energy 
does not come primarily from proteins, as was formerly believed, 
but that the stored glycogen in the muscle is responsible for the 
source of the stored or potential energy of muscle ; that the reduc- 
tion of glycogen means the liberation of such energy of muscle, 



250 PHYSIOLOGY : 

and that the amount of glycogen represents the amount which 
is available for muscular work. 

It has been demonstrated that functioning muscle uses 
glycogen, but there is no appreciable loss of proteins during 
muscle activity. Contracting muscle can use fats to some extent 
as a source of muscle energy in the absence of glycogen. 

Chemical Changes of Active Muscle. — It has been shown 
that there is an excess of carbon dioxide in expired air during 
muscular activity which has resulted from the chemical changes 
of the contracting muscles. The sugars undergo a process of 
splitting, resulting in the formation of lactic acid, etc., and oxygen 
is used up, but, as stated above, the exact chemical mechanism 
is not known. It is definitely known that in contracting muscle 
glycogen and oxygen are used and carbon dioxide and lactic acid 
are liberated. This means, of course, that the arterial supply 
must be good, that the muscle may receive oxygen and have 
its glycogen store replenished as it is used. It also means that 
the venous and lymphatic drainage must be active, that the 
carbon dioxide and lactic acid may be removed. If these pro- 
ducts are not removed they inhibit further muscular activity. 

Muscle Energy. — The reduction changes in glycogen and 
other chemical changes occurring in muscle are probably asso- 
ciated with the action of certain enzymes. 

The reduction of the stored glycogen to sugar is effected by 
the action of an amylolytic enzyme, and the further reduction 
of the sugar is caused by the action of a glycogenic enzyme. This 
seems to be the best explanation of the causes of the energy pro- 
ducing chemical changes. Besides these there are other special 
enzymes, such as a proteolytic enzyme which has the power of 
digesting proteins, a lypolytic or fat-splitting enzyme, and coagula- 
tive enzymes which effect changes of coagulation in injured or 
dead muscle, causing rigor. 

Glycogenetic changes are produced by muscle substances 
(enzymes) which convert the dextrose of the blood to glycogen, 
the latter being stored in resting muscle in quantities varying from 



GENERAL AND OSTEOPATHIC. 251 

.5% to .9% of the muscle by weight. This glycogen, as stated 
above, is during muscular activity converted by the amylolytic 
enzymes to sugars. 

During muscular contraction other less well-known chemical 
substances result. Phosphocarnic acid is produced, but the 
chemistry of the changes producing it are not known. Lactic 
acid is probably an intermediate product of the metabolic process. 
Nitrogen extractives, the nitrogen wastes, such as creatin, uric 
acid, etc., are formed, but their function, if any, in the contraction 
of muscle is not known. 

Energy Liberated in Muscular Activity. — Energy, or 
the power to do work, is liberated in various forms during the 
oxidative changes which occur during muscular activity. Heat 
energy is liberated to some extent from friction, but this is very 
slight. The temperature of frog muscle is increased from .001° C. 
to .005° C. for each contraction. Mammalian muscle is often 
increased as much as one or two degrees as a result of contraction. 

Muscular Work. — The term "work" in the physical sense 
refers to the result of a force applied through a distance and may 
be expressed thus: W=FX, in which W represents the work done, 
F the force applied and X the distance through which the force 
is applied. 

The muscular mechanism is so adjusted that in proportion 
to other machines it does comparatively a greater amount of work 
in proportion to the energy used and the force applied. This is 
because of a more perfect adjustment of the working parts and 
the almost total lack of mechanical friction. 

As compared with the different, well-adjusted engines which 
utilize from 15% to 30% of their applied energy in doing work, 
the muscle machine utilizes from 25% to 30%, or even more, of 
its available energy. About one third of the chemical energy 
liberated is actually used in doing work by the muscular mechanism. 
In some cases, as has been shown by men working at mountain 
climbing (Zuntz), from 35% to 40% of the heat energy produced 
by oxidative processes is utilized in doing work. 



252 physiology: 

Muscular Efficiency. — The term efficiency may be defined 

thus 

Work done (measured in ergs) 



Force applied (measured in dynes) 

It has been shown that the muscle machine has a comparatively 
high efficiency. This again is due to perfectness of adjustment 
and reduced friction. Muscular efficiency varies with different 
muscles and with the musculature of different individuals. Mus- 
cular efficiency may be much increased by proper and well- 
regulated exercises. 

Muscular Power. — The term " power" is, in the physical 

W 

sense, the time rate of doing work and may be expressed P= — 

or power equals the work done divided by the time of doing the 
work. There are certain general propositions which may be 
stated relative to the physical principles of muscular activities, 
and it seems advisable to express these in physical terms: 

1 . The distance through which contracting muscle may act 
varies inversely with the load lifted. This means that the muscle is 
capable of doing a certain amount of work with its available energy 
and no more, thus the application of the formula, W = FX. This 
may be shown by the use of a frog muscle in a muscle-nerve prepara- 
tion. If the muscle be made to contract, lifting a known load, say 
200 gms., it may lift that load through a certain distance, say two 
centimeters. If now the load be increased to 400 gms. and the 
stimulus again applied, the distance lifted is decreased and after 
a time the load may be increased to that point which the muscle 
will not lift. The term " absolute power " of muscle is that amount 
of load which the muscle will not quite lift. 

2. In the physical sense no work is done by active muscle 
if the load is not lifted. 

3. Chemical energy liberated in muscular contraction takes 
the form of heat energy, which is effective in increasing body 
temperature. 

4. A certain optimum amount of load on a contracting muscle 
results in an optimum amount of work. If the muscle for any 
reason is overloaded it will not lift the load to so great a height. 



GENERAL AND OSTEOPATHIC. 253 

and beyond the optimum the proportion is much reduced. (See 
above.) We may conclude from this that muscles have a certain 
limit of efficiency and that any strain beyond this limit markedly 
reduces the ability to do work. 

Muscular Tension. — It has been shown that muscle is 
capable of resisting a comparatively great load without injury. 
Frog muscle can lift a weight of from 500 to 3,000 grams per 
cross sectional area of one square centimeter, and human muscle 
has a maximum tension of about twice this amount. 

Fatigue of Muscle Tissue. — Some of the causes and condi- 
tions of muscular fatigue have been discussed. The chemical 
changes involved in fatigue are to be given here. The knowledge 
of some of the phenomena of fatigue will assist in an understanding 
of the chemical nature of the changes occurring: 

1. If a muscle be allowed to rest after fatigue, recovery 
results. It would seem that this rest is needed for several purposes 
— to restore the used glycogen content, to repair tissue waste, and 
to allow time for drainage of the products of muscle metabolism. 

2. If the blood supply is reduced to acting muscle it fatigues 
more quickly. If the blood supply is reduced after fatigue, the 
length of time of recovery is increased. If the blood supply is 
completely shut off from a fatigued muscle recovery does not 
occur. 

These facts are easily understood, and simply mean that the 
muscle is capable of only a certain amount of work from its store 
of glycogen and other substances and that these must be supplied 
for functional restoration of a fatigued muscle. 

3. If the venous drainage be interfered with, the same con- 
ditions as given under 2 will occur. This means that during 
contraction certain waste products are formed, and that these 
must be removed before functional activity of the fatigued muscle 
can be restored. 

That these waste products inhibit contraction the following 
evidence may be offered: That extract of fatigued muscle when 
injected into the blood stream of a normal animal inhibits contrac- 
tion in that animal. Control tests of this experiment have been 



254 PHYSIOLOGY : 

made by the injection of extracts of unfatigued muscle, which 
gave no result. 

The fatigue, then, is due to two things : First, the deprivation 
of the muscle of its store of chemical supplies, and second, the 
collection of the products of muscle metabolism, e. g., lactic acid, 
carbon dioxide, acid potassium phosphate, etc. 

The oxygen supply in addition to other substances furnished 
by the arterial blood is also necessary for the production of the 
oxidative changes, which occur during muscular activity. 

CAUSES OF MUSCULAR CONTRACTION. 

The source of energy for muscular contraction is the stored 
glycogen and the ultimate cause is the reduction of the glycogen, 
or more especially the sugars resulting from the glycogen, but 
how the energy thus liberated is used in producing the shortening 
of muscle is certainly not well known. 

As regards the direct cause of the shortening and thickening 
of the fibers which is known to occur in muscular contraction many 
theories have been advanced, some of which will be briefly given. 

The theory advanced by Fick is that the contraction is directly 
due to increased chemical affinity. Weber held the idea that 
the contraction was due to an increased elasticity, caused by 
changes effected by the stimulation. Muller believed that the 
stimulus caused certain electrical changes in the muscle, causing 
attraction and repulsion. Changes in surface tension caused 
by the chemical changes occurring as a result of stimulation has 
been suggested. By this means it is supposed that the fibrils 
may be made to shorten. 

At present the heat theory of Engelmann is receiving much 
attention. This theory assumes that the double refractive sub- 
stance in contractile tissue plays an important part in that this 
substance absorbs the light bands of the singly refractive sub- 
stances, thus causing the shortening of the fiber. Engelmann 
has further shown that non-living substances, such as catgut, 
when well soaked in water will shorten when heated and will 



GENERAL AND OSTEOPATHIC. 255 

relax again when cooled. He explains this action by assuming 
that the heat produced in the muscle causes the absorption of 
water and that the absorption of the light bands may.be similarly 
explained. The immediate cause of the shortening according to 
this theory is the inhibition of water or other substances as a 
result of the heating. By placing a piece of well-soaked catgut 
within the coils of a platinum wire or other conductor and passing 
an electric current through the coil it may be demonstrated that 
the gut will be caused to shorten as a result of the heat thus pro- 
duced. 

There seems to be another possible explanation of the effect 
of the heat produced by the chemical changes. It is known that 
a sphere is that form of a solid which contains the greatest possible 
content per surface area and it is further known that according 
to Charle's law the volume of a liquid or gas is correspondingly 
increased as the temperature is increased. Now, assuming that 
this law holds for the fluid content of the muscle cell, it would be 
reasonable to suppose that, if the temperature were increased the 
cell would necessarily shorten and thicken in an attempt to ap- 
proach the form of a sphere, when its liquid content were heated. 
This seems reasonable as a supposition, but it is hardly probable 
that this factor alone could account for the amount of shortening 
when -the temperature changes are so slight. 



SECTION VII 



NERVE TISSUE 



CHAPTER XXIX. 

STRUCTURE AND FUNCTION OF 
NERVE TISSUE. 

The Nerve. — The term nerve is usually applied to a nerve 
trunk, which consists of hundreds or even thousands of separate 
nerve fibers. Each of these nerve fibers is an independent unit, 
destined to carry its own impulse to or from the cord or brain 
and in this way to regulate the functional activity of some special 
structure. The different nerve fibers are contained in supportive 
connective tissue known as endoneurium and the different fiber 
bundles are contained in other supportive tissue known as the 
neuroglia. 

Structure and Function of the Nerve Fiber. — The nerve 
fiber consists of a central part, the axis cylinder, which is an elon- 
gated process of the protoplasm of the nerve cell. The axis cylin- 
der contains many smaller threadlike fibers which are contained 
within an interfibrillar substance, the neuroplasm. It is generally 
considered that these neurofibrils are the true conductive media 
of the nerve fiber. The axis cylinder is surrounded by a covering 
known as the medullary or myelin sheath, known also as the 
sheath of Schwann. At regular intervals the myelin sheath dips 
in against the axis cylinder, causing the sheath to be segmented. 
These folds are known as the nodes of Ranvier. This causes 
the sheath to consist of nodes and internodes, each segment having 
its own nucleus which probably acts as its trophic center. The 
myelin sheath consists of fatty material, composed principally 
of lecithin, which is contained within the interstices of a firmer 
substance known as the neurokeratin. The medullary sheath 
is considered to have three general functions, as follows: 1. It 
is supposed to act as an insulator in that it prevents the leakage 

259 



260 physiology: 

of nerve impulse from the axis cylinder. As evidence of this it 
may be mentioned that those structures in which the most exact 
functioning is required, such for example as striated muscle 
tissue, are supplied by medullated nerve fibers, while other struc- 
tures are often supplied by non-medullated fibers. It is also known 
that the main tracts of the cord do not become functional until 
the medullary sheaths of these fibers have been developed; 2. 
A second function of the medullary sheath is that of trophism. 
The medullary sheath probably furnishes nutrition to the axis 
cylinder and its contents, especially in the long nerve fibers. As 
evidence of this it may be mentioned that a thicker myelin sheath 
covers those nerve fibers which take the longer courses, since 
these structures could not be so well nourished from the cell body 
of which they are a part; 3. A third function of the myelin sheath 
is that of protection. 

The medullary sheath is surrounded by another sheath, 
the neurilemma or primitive sheath. All of the above named 
structures developmentally are derived from the ectoderm with 
the possible exception of the neurilemma, which probably comes 
from the mesoderm. 

The axis cylinder with its contents, the neurofibrils, is an 
outgrowth of protoplasm from the nerve cell, which serves as 
the nutritional and dynamic center to all the processes of the 
cell. 

Medullated and Non- Medullated Fibers. — The medul- 
lated fibers are so called because they are covered by the medullary 
or myelin sheath. These fibers vary greatly in size. The larger 
medullated fibers are distributed to striated muscle and skin 
surfaces, while the smaller medullated fibers are distributed to 
the internal viscera. These visceral fibers are not distributed 
directly to the viscera by way of one continuous fiber process, 
but terminate in different collections of cells known as ganglia, 
some of which lie in the lateral chains and others in peripheral 
ganglia. From these ganglia other non-medullated fibers arise 
which carry the nerve impulses to the structure supplied. All 
nerve fibers belonging to the central nervous system, that is, 



GENERAL AND OSTEOPATHIC. 261 

all of those which enter or leave the brain or spinal cord, are of 
the medullated type. 

The non-medullated fibers differ from the medullated fibers 
in that they are not possessed of a medullated sheath, but have 
in most cases a primitive sheath or neurilemma. Ultimately 
these fibers break up into a network of many smaller fibers and 
the sheath which covers them is lost. 

Nerve Conduction. — Just as muscle tissue is classed as 
contractile tissue, because its chief and only function is that of 
contractility, nerve tissue may be considered as conductive tissue, 
this being its only function. Conduction may be defined as the 
propagation of an impulse over a nerve fiber as the result of a 
reaction to stimulus. The nerve fiber with all of its parts con- 
stitutes a special structure for the performance of a special function. 
The neurofibrils of the axis cylinder may be considered as the true 
conductive medium, while other parts act as insulators and other- 
wise aid the axis cylinder in the performance of its function. 

The Nerve Impulse. — Many theories have arisen relative 
to the nature of the nerve impulse. It was once believed that 
nerves consisted of tubes, whose function was to carry a kind of 
gas or spirit (animal spirit or nerve juice), which caused the func- 
tional changes in the structure supplied. This theory has, of 
course, been completely abandoned and other theories more 
scientific in nature have taken its place. The results of more 
recent research work on the subject have shown that the nerve 
impulse resembles to some extent the electrical charge as it passes 
over its conductor. The relations between the electrical current 
and the nerve impulse may be summarized as follows : The nerve 
impulse travels at a rate of about thirty-four meters per second 
(Helmholtz). Other research workers have estimated the rate 
of nerve impulse to be much greater than this. Piper estimates 
the rate of nerve impulse to be from 117 to 125 meters per second. 
In either case the rate of conductivity of nerve impulse is much 
greater than the rate of conductivity of the electrical current, 
which is less than 27 meters per second. The direction of con- 
duction also varies, as the electrical current may be conducted 



262 physiology: 

in either direction over its conductor, while the conductivity of 
nerve impulse is normally only in one direction. The direction 
of the conduction of nerve impulse by way of the axis cylinder 
of the axon is always away from the cell body, and may be said 
to be cellulifugal, while the conductivity of the dendrites is always 
towards the cell, or cellulipetal. A nerve trunk may be made to 
conduct in either or both directions if stimulated artificially in 
its mid-portion, but when normally stimulated by its cell body 
the impulse travels only in one direction. 

Variations in Conductivity. — The conductivity of a nerve 
fiber may be influenced as to its rate and force of the impulse by 
many conditions, as follows: 1. Any increase in temperature 
increases the rate of conductivity in homeothermous animals 
up to a temperature of 50° C. Between normal temperature 
and that of 50° C. the rate of conductivity seems to vary directly 
with the temperature. Any decrease in temperature decreases 
the power of conduction and conductivity is lost at a temperature 
of 0° C. ; 2. Compression of a nerve trunk retards or even destroys 
the power of conductivity and may do so without permanently 
injuring the nerve. This fact is of some osteopathic significance 
in that osteopathic lesions may in this way interfere with the 
normal conductivity of the nerve impulse and thus interfere with 
the functional activities of the structures supplied by the nerve 
involved; 3. Conductivity of nerve impulse varies directly with 
the oxygen supply to the nerve center and its processes. Since 
the oxygen supply to nerve as well as all other tissues is furnished 
by the arterial blood, we can readily see an application of Dr. 
Still's statement: "The rule of the artery is supreme." It is a 
well-known fact to osteopathic physicians from their clinical 
experience and has been repeatedly shown by the results of osteo- 
pathic research workers that an increase of the blood supply to 
nerve centers will cause an increased functional activity of the 
structures supplied by nerve fibers from these centers; 4. Any- 
thing which retards the venous or lymphatic drainage from a 
nerve cell or its processes retards the power of conduction by way 
of the nerve fibers. This condition follows as a result of the 



GENERAL AND OSTEOPATHIC. 263 

effects of products of cell metabolism, which act as toxic sub- 
stances to the cell when their removal is not properly effected. 
It should be remembered, as Sherrington explains, that "in the 
first place, nerve-cells, like all other cells, lead individual lives, — ■ 
they breathe, they assimilate, they dispense their own stores of 
energy, they repair their own substantial waste; each is, in short, 
a living unit, with its nutrition more or less centered in itself. 
Here, then, problems of nutrition, regarding each nerve-cell and 
regarding the nervous system as a whole, arise comparable with 
those presented by all other living cells." We see from this 
understanding of the nerve cell that it is just as essential for the 
products of metabolism, such as carbon dioxide and other metabolic 
products, to be removed from the cell by a normally functioning 
lymph and venous drainage system as it is for these cells to be 
supplied by normal blood by way of the artery. It is well known, 
as has been shown by clinical and experimental evidence, that 
osteopathic lesions often retard the drainage of such products 
and in this way the lesion indirectly retards the rate of conduc- 
tivity of the nerve impulse and decreases its power of functional 
activity; 5. Nerve conductivity is decreased or completely 
stopped by conditions of narcosis as a result of the administration 
of certain drugs, such as ether, chloroform, cocaine, chloral, phenol, 
alcohol, etc.; 6. Fatigue of a nerve fiber also reduces its power 
of conductivity, but conditions of fatigue of nerve tissue are not 
very thoroughly understood. Nerve tissue is commonly consid- 
ered as being non-fatigable by continued functional activity, 
like other structures, but there are certain conditions which can 
hardly be explained other than by assuming that nerve tissue is 
to some extent fatigable. After one impulse has been discharged 
over a nerve fiber there is a period, although very short (.006 of 
a second after the first stimulation), during which time the nerve 
is inactive and will not conduct a second impulse. This is known 
as the refractory period. It has never been shown that there 
is any marked increase in the metabolic activities of the nerve 
during conductivity, and its temperature is only increased during 
conductivity .005° C. It is therefore argued by some that for 



264 PHYSIOLOGY : 

this reason the nerve does not fatigue during the passage of the 
impulse. There are certain conditions, however, in which nerve 
tissue is known to become non-functional from excessive activity 
(fatigue of the olfactory nerve, which diminishes or completely 
destroys for a time the sense of smell), and it is probable at least 
that all nerve tissue is fatigued to some extent from excessive 
activity. 



CHAPTER XXX. 

FUNCTIONAL DIFFERENCES IN NERVE 

FIBERS. 

Since there are hundreds or thousands of separate and indi- 
vidual fibers in each nerve trunk and since so many different 
functional activities are to be initiated and regulated by these 
fibers, it would seem necessary for a wide degree of variation in 
the functional nature of the different fibers composing the dif- 
ferent nerve trunks. This is found by experimental investigation 
to be true and that, while structural differences in the different 
nerve fibers constituting the nerve trunk may not be possible 
of demonstration, the functional specificity may be demonstrated. 
The reason for this specificity will be discussed later. 

Direction of Conduction. — As has been explained, the 
dendrites of the neuron always conduct towards the cell body 
(cellulipetal conduction) and the axon always conducts from the 
cell to the peripheral structures supplied or to ganglia or dendrites 
of other cell bodies (cellulifugal conduction). The results of the 
notable work of Bell and Magendie first showed that the same 
nerve fiber can conduct only in one direction. Before this time 
physiologists had supposed that nerve fibers might be either 
motor or sensory. 

Afferent and Efferent Fibers. — The terms motor and 
sensory, as applied to the direction of conduction in nerve fibers, 
is now known to be inaccurate, as not all outgoing fibers are des- 
tined to cause contraction in muscle tissue and not all incoming 
fibers are destined to cause sensation. As to the direction of 
conduction nerve fibers are more properly classified as efferent, 
referring to those neurons whose axones conduct impulses from some 
cell body in the brain, cord, or some ganglia to structures such as 
muscles, glands, etc., situated peripheral to its cell of origin. 

265 



266 PHYSIOLOGY I 

Afferent neurons are those whose cell bodies lie for the most part 
near the cord or brain stem (in ganglia of the posterior root and 
ganglia of the cranial nerves), whose dendrites extend from some 
peripheral structure or ganglion to this cell body, and whose axon 
extends to some center or centers within the cord or brain. Af- 
ferent fibers normally receive their stimuli only at their peripheral 
endings and efferent fibers normally receive their stimuli only 
from their cells of origin. The difference in direction of conduc- 
tivity, therefore, depends upon this structural difference of the 
neurones, namely, that the dendrites conduct towards their cells 
of origin, while the axons conduct away from their cells of origin. 

The Bell-Magendie Law. — These workers, as mentioned 
above, discovered that nerve fibers conduct normally in only one 
direction and that all efferent (motor) fibers of the spinal nerves 
emerge from cell bodies located in the anterior gray matter of 
the spinal cord and pass out by way of the anterior roots. After 
passing through the intervertebral foramina these efferent fibers 
are distributed with the anterior and posterior divisions formed 
from this segment, and by these nerve trunks and their branches 
they are distributed to the various tissues supplied. These authors 
also showed that only afferent or ingoing fibers (sensory) were 
contained in the posterior roots. This law may be stated briefly 
as follows : The anterior roots of the spinal cord are strictly efferent 
and the posterior roots are strictly afferent in function. The 
principles of this law have many times been attacked, but no 
positive evidence has as yet been established against the law as 
stated. 

Afferent and Efferent Fibers Specific in Function. — 
All afferent and efferent neurons may be further classified as 
regards the nature of their specific functions into excitatory and 
inhibitory fibers. By the term excitatory is meant that when 
these special fibers are stimulated the cells of the structures which 
they supply are excited to greater activity, and conversely when 
those fibers known as inhibitory fibers are stimulated the cells 
of the structures which they supply have their functional activity 
decreased and they are, therefore, properly called inhibitory fibers. 



GENERAL AND OSTEOPATHIC. 



267 



Excitatory and inhibitory fibers may be subdivided into 
many divisions according to their various specific functions. The 
following table of classification, as given by Howell, is quite ex- 
planatory : 



Excitatory 



Efferent . . ^ 



Inhibitory 



Motor 



Secretory 



Inhibito- 
motor . . . 



f Motor 
j Vasomotor 
-j Cardiomotor 
| Pilomotor 
[ Viscero -motor 

f Salivary 
! Gastric 
j Pancreatic 
I Sweat 

i Subdivisions corresponding to the 
\ varieties of motor fibers above 



Excitatory 



< 

Inhibito- ^ Subdivisions corresponding to the 
I secretory -j varieties of secretory fibers above 



f Visual 
Auditory 
Olfactory 

, Gustatory 
Sensory . . -j Pressure 

Temperature 

Pain 

Hunger 

t Thirst, etc. 



Afferent. 



L Reflex, 



(_ Inhibitory 



.j Inhibito- 
( reflex 



j According to the efferent fibers 
I affected 

f Inhibitory effects upon the conscious 

sensations are not demonstrated 
1 The reflex fibers that cause unconscious 
j reflexes are known to be inhibited in 
[ some cases at least 

The term "motor" is applied to those nerve fibers, efferent 
in function, which supply muscle tissue (somatic efferent), the 
striated muscle tissue being supplied by the efferent spinal nerves, 
whose cell bodies lie in the anterior horn of the spinal cord and 
whose fibers are distributed by way of the spinal nerves. Smooth 
muscle tissue is supplied by autonomic efferent fibers (visceral 
efferent), whose cell bodies lie in the antero-lateral part of the 
spinal cord and whose axones are distributed by way of the splanch- 



268 physiology: 

nic fibers to the tissues supplied. The vasomotor fibers, con- 
strictors and dilators, are also autonomic effe'rents, which ma}' 
be distributed either with the splanchnic fibers to the small arteries 
of the viscera or by way of the spinal nerves to the vessels within 
the structures which these nerves supply. The cardio-motor fibers 
are those which regulate the heart and are also autonomic. The 
inhibitory fibers are distributed to the heart by way of the vagus 
nerve and the accelerators by way of the spinal autonomics. These 
latter fibers are thought by some authorities to consist of two 
groups functionally: namely, the accelerators proper, which in- 
crease the rate of the heart beat, and the augmentors, which 
increase the force of contraction of the heart. The viscero-motor 
fibers are distributed to the different organs by way of the cranial 
and spinal autonomics. They are divided into two groups, namely, 
the motors, stimulation of which increases the contraction of the 
smooth muscle of the viscera, and the inhibitors, stimulation of 
which decreases the contraction of the muscles of the viscera. 
The pilomotor fibers are those which supply the muscles of the 
hair follicles. These are also autonomic fibers. Secretory fibers 
are usually of two kinds, namely, those which are supplied to the 
glandular cells and seem to control the manufacture of zymogen 
granules or other substances produced by these cells and may 
be said to be trophic in function, while the other group of fibers 
(secretory proper) control the output of the secretions and deter- 
mine the quantity of secretion produced. For specific examples 
of these the reader is referred to the mechanism of secretion of 
the salivary glands. Some authorities have also described inhibi- 
tory secretory fibers, the stimulation of which retards the func- 
tional activity of secretory glands. It may be that the functions 
of glandular tissues are regulated by many different types of 
nerve fibers, the functional nature of which is not at present 
understood. The nature of the specific actions of those fibers 
associated with the special sense organs will be found discussed 
under the physiology of those structures. Specific reflex fibers 
afferent in function are classified according to the nature of the 
change produced by efferent nerves stimulated by their reflex 



GENERAL AND OSTEOPATHIC. 269 

effects. As an example of this we may mention the " pressor 
fibers," the stimulation of which affects the vaso-constrictor center 
or centers and thus reflexly causes an increase in systemic blood 
pressure. Those afferent fibers, the stimulation of which causes 
excessive activity of the vaso-dilator center or which in some 
other way causes reflexly systemic or local vaso-dilation, and 
therefore a decrease in blood pressure, are known as " depressor 
fibers." There are many other examples of specific reflex 
afferent fibers which cause definite physiological changes. It 
is highly probable that it is by the normal stimulation of the 
peripheral endings of these specific afferent reflex fibers that the 
various bodily functions are regulated in such a way that the 
functional activities of the organism as a whole are adjusted to 
its environment. 

Mechanism of Specificity of Nerve Energies. — Since 
it has been shown that there is so much specificness of function in 
the various nerve fibers constituting the nerve trunks, it seems 
advisable to discuss the nature of the causes of this specificity. 

There are several possible ways in which specific effects could 
be produced as follows: 

1. The specificness of action might be due to some struc- 
tural difference of the nerve fibers, but this does not seem probable, 
as no structural differences can be demonstrated histologically 
in certain nerves, which are known to have wholly different func- 
tions. 

2. Specificness of function of nerve fibers might also be 
explained by assuming that there is a difference in the nature 
or force of the impulse, but "The usually accepted view is that 
they are identical in character in all fibers and vary only in inten- 
sity. According to this view, a sensory nerve — the auditory nerve, 
for instance — carries impulses similar in character to those passing 
along a motor nerve, and the reason that in one case we get a 
sensation of hearing and in the other a contraction of a muscle 
is found in the manner of ending of the nerve, one terminating 
in a special part of the cortex of the cerebrum, the other in a 
muscle." (Howell.) 



270 physiology: 

3. It is probable that the nature of the end organ plays 
no small part in determining the nature of the impulse trans- 
mitted by way of the nerve. The end organ is in many cases 
of such a nature that it can be receptive to only certain kinds of 
stimuli. For example, it may be stated that the olfactory end- 
ings are susceptible to stimulation only by substances in the 
gaseous state, while the taste buds are sensitive to stimulation 
only by substances in the liquid state. The organs of Corti 
of the cochlea react only to vibratory stimuli. There are many 
different sensory endings (sensory receptors) of the skin surfaces 
which are specific, such for example as the well-known cold areas, 
warm areas, pain areas, pressure areas, etc. It may be seen, 
therefore, that the endings, or, we should say, the nature of the 
sensory receptors, have much to do with the determination of 
the stimuli received by their selective action. This mechanism 
explains only how certain kinds of stimuli or the stimuli produced 
by certain conditions are transmitted to specific nerve fibers. 
The stimuli received by these fibers is in turn transmitted to 
certain specific brain centers and it may be, in fact it is most 
probable, that the analytic and association function of these 
cortical centers have most to do with the ultimate determination 
of the nature of the stimulus received. The nerve fiber itself 
probably plays no important part in this kind of specific function- 
ing. Stimulus by way of the optic nerve produces sensations 
of light. The normal stimulus to the optic nerve is light, which 
stimulates its end organ, the retina, but if the nerve be sectioned 
and artificial stimulus be applied to its central end a sensation 
of light will also result; so we see that the brain center, in some 
specific cases at least, is responsible for the function, which would 
seem to be due to the end organs. 

4. The most probable explanation of the mechanism of 
specificity is that the receptive centers in the brain so analyze 
and associate their incoming impulses that the individual is 
enabled to determine the nature of the environmental or body 
conditions causative of the stimulus. It has been pointed out 
above how in seemingly very specific cases, where the end organs 



GENERAL AND OSTEOPATHIC. 271 

are highly differentiated, such as the eye, the ultimate determina- 
tion of the specificity is the brain center or centers. "On the 
identity theory of the nerve impulses the specific energies of the 
various nerves — that is, the fact that each gives only one kind of 
response — is referred entirely to the characteristics of the tissue 
in which the fibers end. If, as has been said, one could success, 
fully attach the optic nerve to the ear and the auditory nerve to 
the retina then we should see the thunder and hear the lightning. ' ' 
(Howell.) 

It has also been shown that in the case of efferent fibers cer- 
tain nerves the effect of which is to regulate the functional activity 
of glandular tissue, the result is due to the nature of the struc- 
ture in which the efferent nerve terminates. If, for example, 
the nerve supplies to the parotid gland be switched, i. e., the 
cranial autonomic fibers (nerve of Jacobson) be cut and their 
peripheral ends attached to the central end of the cervical auto- 
nomics, and conversely the peripheral end of the cervical autonomic 
fibers be connected to the central end of the cranial autonomics 
and time be allowed for regeneration, stimulation of these nerves 
causes just the opposite effect when stimulated; i. e., the cranial 
autonomic fibers, instead of producing vaso-dilation and secre- 
tion as they normally should do, now produce vaso-constriction, 
and on the other hand stimulation of the spinal autonomic 
fibers (cervical sympathetics) is followed by vaso-dilation and 
secretion, which functions normally belong to the cranial auton- 
omic fibers. (See nerve mechanism of secretion of saliva.) 



CHAPTER XXXI. 
PHYSIOLOGY OF THE NERVE CELL. 

The Neuron Doctrine. — The main points of the neuron 
doctrine may be briefly stated as follows: 1. That the struc- 
tural and functional units of the nervous system are the neurons 
has been established; 2. These neurons are not structurally 
connected, that is, there is no anatomical continuity of the fibers 
of different neurons, but there is a contact communication be- 
tween different neurons; 3. That the processes of the nerve cell, 
the axon and dendrite or dendrites, are structurally and func- 
tionally parts of the cell and with the nerve cell constitute a com- 
plete functional unit, has also been established; 4. It is also 
known that nerve trunks consist of great numbers of these pro- 
cesses of nerve cells, both axones and dendrites; 5. The direction 
of conduction in the neurons is normally always towards the 
cell in the dendrites and away from the cell in the axones; 6. 
The impulse or " nerve current'' is transmitted from one neuron 
to another by a contact (the synapse). Very little is known 
relative to the nature of this synaptic connection so far as the 
structural mechanism is concerned, but its functional nature is 
better understood, as will be shown later. The axon of one neuron 
connects or in some way is associated with another or others by 
terminating about the dendrites or cell bodies of the second neuron. 
By this arborization there seems to be an imperfect connection 
formed from one neuron to another, by means of which the im- 
pulses are transmitted. 

The Synapse. — Many different views have been advanced 
relative to the structural nature of the synapse, but there is as 
yet very little known about it. Some of the different views are 
as follows: 
272 



GENERAL AND OSTEOPATHIC. 273 

1. The theory that the neurofibrils of one neuron are co- 
extensive with the same structures of other neurons is not gener- 
ally accepted as an explanation of the histological nature of the 
synapse in the higher forms of animal life. It has been established, 
however, that such structures actually exist in some of the lower 
forms of life (the medusae). 

2. The theory of the existence of some kind of contact asso- 
ciation between the axons of one cell and the dendrites of another 
seems to be a better explanation. The nature of this contact, 
however, is certainly not at the present time at all understood. 

3. Other authorities believe a membranous division may 
exist, the resistance of which in some way influences the passage 
of the impulse from axon to dendrite or from axon to cell body. 
Concerning this view we quote from Sherrington as follows: 
"If the conductive element of the neuron be fluid, and if at the 
nexus between neuron and neuron there does not exist actual 
confluence of the conductive part of one cell with the conductive 
part of the other, e. g., if there is not actual continuity of physical 
phase between them, there must be a surface of separation. Even 
should a membrane visible to the microscope not appear, the mere 
fact of non-confluence of the one with the other implies the exist- 
ence of a surface separation. Such a surface might restrain dif- 
fusion, bank up osmotic pressure, restrict the movement of ions, 
accumulate electric changes, support a double electric layer, 
alter in shape and surface-tension with changes in difference of 
potential, alter in difference of potential with changes in surface- 
tension or in shape, or intervene as a membrane between dilute 
solutions of electro-lytes of different concentration or colloidal 
suspensions with different sign of charge. It would be a mechan- 
ism where nervous conduction, especially if predominantly 
physical in nature, might have grafted upon its characters just 
such as those differentiating reflex-arc conduction from nerve- 
trunk conduction. For instance, change from reversibility of 
direction of conduction to irreversibility might be referable to 
the membrane possessing irreciprocal permeability." 



274 physiology: 

The rate of nerve conductivity is probably the same in the 
tracts of the cord as in the nerve trunks, but there seems to be a 
marked delay in the speed of the impulses as they pass from the 
white to the gray matter, the so-called " latent period of reflex 
action." "The delay in the gray matter may conceivably be 
due to slower conduction in the minute, branched, and more 
< iff use conducting elements — perikarya, dendrites, arborizations, 
etc. — found there ; or it may be referable to a fresh kind of trans- 
mission coming in there, a process of transmission different in 
nature to conduction along nerve-fibers. The neuron itself is 
visibly a continuum from end to end, but continuity, as said 
above, fails to be demonstrable where neuron meets neuron — at 
the synapse. There a different kind of transmission may occur. 
The delay in the gray matter may be referable, therefore, to the 
transmission at the synapse. 

"And if the delay occur at the synapse, the possibility suggests 
itself that the time consumed in the latent period may be spent 
mainly in establishing active connection along the nervous-arc, 
which connection once established, the conduction in the arc 
then proceeds perhaps as speedily as does conduction in a simple 
nerve-trunk. The latent time would then be comparable with 
time spent in closing a key to complete an electric circuit or in 
setting points at a railway junction. The key once closed, the 
points once set, the transmission is as expeditous there as else- 
where/' (Sherrington.) The osteopathic significance of the 
reflex arc will be discussed under another heading. (See index.) 

Relation of the Nerve Cell to Its Processes. — As has 
been previously stated, the processes of the nerve cell — the axon 
and dendrites — are embryologically and anatomically parts of 
the cell, and taken together these parts constitute a functional 
unit. Separated from the cell, as a center, these processes are 
functionless. Developmentally the cell body is the structural 
and functional center of the neuron. The cell body appears 
first, then the processes develop by growing out from the cell. 
That the nerve cell is the nutritional center of the neuron was 
first shown by Waller, who demonstrated that, if a nerve trunk 



GENERAL AND OSTEOPATHIC. 275 

is severed from its cells of origin, the peripheral part will degen- 
erate. The time of degeneration occurs in from three to ten days 
after the section is made, the process being known as Wallerian 
degeneration. The degeneration always occurs in that part of 
the nerve process, axon or dendrite, peripheral to its cell of origin. 
That part which remains connected to the nerve cell does not 
degenerate except for a small part (two or three nodes of Ranvier) , 
which may be due to direct injury occurring from the trauma of 
the sectioning. Although it is positively known that the cell 
is the nutritional or trophic center, it is not well understood how 
the cell body regulates this function over its processes. It may 
be that this nutritional function is effected by the activity of the 
axon which results from the dynamic force of the cell, which view 
would consider the degeneration as a result of disuse or inactivity. 
Another theory is that some kind of nutritive substance is actually 
carried from the cell to the processes. 

Practical Significance of Degeneration. — This physio- 
logical fact is of value in tracing the courses of nerve fibers in the 
central nervous system. For example, if the anterior roots of 
one or two segments of the spinal cord be sectioned, the degenera- 
tion is always peripheral to the cells of origin, which lie in the 
anterior root of the cord. The degeneration, therefore, occurs 
in the efferent nerve trunks, which extend to and supply the 
muscles and other viscera. If the posterior root be sectioned, 
the direction of the degeneration depends upon whether the sec- 
tion is made central or peripheral to the ganglion on the posterior 
root. If the section is central to the ganglion, that is, between 
the ganglion and the spinal cord, the degeneration occurs in the 
tracts in the cord (the axons, which ascend brainward.) If the 
section be made peripheral to the cells of origin, that is, peripheral 
to the ganglion on the posterior root, the degeneration occurs 
in the incoming fibers, the dendrites, from the peripheral struc- 
tures. If the spinal cord itself be sectioned or hemisected, or 
if degenerative changes occur from pathological lesions in the 
cord, the efferent fibers (fibers going from the brain to be dis- 
tributed to the various cells of the cord) degenerate peripheral 



276 PHYSIOLOGY : 

to the point of lesion. On the other hand, the afferent fibers 
(axones extending from the ganglion on the posterior root or 
from cells in the cord) which are going brainward degenerate 
central to the lesion or beween the lesion and the brain or upper 
cord termination. It will be seen, therefore, that the cells of 
the ganglion on the posterior root and the cells in the brain and 
cord, as well as the cells of the anterior horn (motor cells) act as 
trophic centers to their processes, the axones and dendrites. The 
same form of reaction of degeneration has been shown to hold 
good for the cranial nerves. 

Since it is known that this process of degeneration occurs 
only in living neurons and since any severe injury to nerve cells 
or nerve trunks is constantly followed by such changes, the nature 
of the degeneration, that is, the functional disturbances, occurring 
in the structure supplied, such as paralysis, atrophy, etc., are 
usually safe guides to the source of the injury or pathological 
lesion causative of the condition. The length of time necessary 
for degeneration varies somewhat with different nerves and varies 
very greatly with different animals. In warm-blooded or homeo- 
thermous animals the degeneration often appears to begin within 
a few hours after the injury and is complete in the course of a 
few days, while in cold-blooded or poikilothermous animals the 
rate of degeneration is much slower, often requiring weeks or 
even months. In some instances in which the cause of the de- 
generation is some infectious or toxic agent affecting the nerve 
cell, the process may be slow and progressive, but even in these 
cases the loss of function in the structures supplied is often of 
sudden occurrence. 

Nerve Regeneration. — Regeneration is a result of the 
process of development of new fibers from the old nerve cell in 
the path of the old (degenerated nerve trunk). Nerves do not 
grow back together after section. It makes no difference how 
soon the attachment of the nerve end be made after the section, 
there is never any " healing by first intention," as may occur 
in other structures. There is some difference of opinion as regards 
the nature of the regeneration. Howell states that " The regenera- 



GENERAL AND OSTEOPATHIC. 277 

tion is due to the activity of the nuclei of the neurilemmal sheath. 
These nuclei begin to multiply and to form around them a layer 
of protoplasm, so that as the fragments of the old fiber disappear 
their place is taken by numerous nuclei and their surrounding 
cytoplasm. Eventually there is formed in this way a continuous 
strand of protoplasm with many nuclei, and the fiber thus pro- 
duced, which has no resemblance in structure to a normal nerve 
fiber, is described by some authors as an 'embryonic fiber'; by 
others as a 'band fiber'." 

After this first, "the initial stage," of regeneration has been 
completed the process ceases unless the peripheral end becomes 
attached to the central end of the old nerve, but this connection 
always results unless experimentally or accidentally prevented. 
The connection with the nerve cell by way of the central end of 
the old nerve trunk, "the band fibers", are quickly "transformed 
into a normal nerve fiber, with myelin sheath and axis cylinder. " 
The axis cylinder is probably a result of extension outward of the 
original axis cylinder from the old nerve trunK, which has remained 
attached to the cell. The axis cylinder of the nerve stump probably 
finds its way into the newly formed nerve by a process of chemo- 
tropism (specific chemo taxis), as a result of the nerve tissue hav- 
ing a greater attraction for nerve tissue than for any otuer kind 
of tissue. There is little danger that the new, outgrowing, 
nerve will fail to connect with the peripheral end of the old, de- 
generating trunk because of this force which tends to bring them 
together. 

Classification of Neurons. — The classification most com- 
monly used considers the different types of neurons structurally 
under two general groups, as follows: 

1. Bipolar cells. During the process of development the 
processes of these cells are so folded together that in the adult 
animal they may appear to arise from the cell as one common 
process, and the cell therefore appears to be unipolar. Soon 
after leaving the cell these two processes separate and take inde- 
pendent courses. One is the axon, the other the dendrite. The 
axon in the spinal nerves extends cordward and thence by way 



278 physiology: 

of the asdending columns of the cord it extends brainward, while 
the dendrite extends to some sensory or other receptive surface. 
In case of the cranial nerves the axon extends brainward and the 
dendrite extends to some special or other receptive surface. The 
processes of these fibers develop medullary sheaths and the two 
processes with the cell body constitute an afferent neuron. Neu- 
rons of this type are found in the ganglia of the posterior root, 
in the spinal nerves and many cranial nerves. Development ally 
these nerve cells originate from certain neural-crest cells, which 
have come primarily from the primitive folding of the ectoderm 
in the process of formation of the neural tube. These masses 
of neural-crest cells migrate ventrally (they are bilateral struc- 
tures) , and those cells which are destined to form the cells of the 
ganglion of the posterior root assume a position in close relation 
to the growing cord. Their axones grow into the cord. Some 
enter into synaptic relations with other cells and dendrites of 
other cells of the cord, while others extend upward or downward 
to form association connections and to form the long ascending 
columns. The dendrites of these cells during the process of 
development grow peripherally and constitute a part of the trunks 
of the spinal nerves. Since the dendrites always conduct towards 
the cell and since the axones always conduct away from the cell, 
it will be readily seen that these neurons could be only afferent 
in function. This hint on the development of these fibers ex- 
plains why the fibers of the posterior horn are always afferent in 
function, and further explains a part of the law of Bell and Magen- 
die. It seems well to add here that the rest of the cells of the 
neural-crest mass, that is, those which continue their migration 
ventrally, are destined to become the cells of the ganglia of the 
lateral chain and possibly of the peripheral spinal autonomic 
plexuses. It will be seen by more thorough study of the embry- 
ological development of the nervous system that all afferent nerves 
develop from cells lying outside of the central nerve axis, and 
because they must by this process of development grow into it 
they must also conduct towards the cord or brain, or both, and 
thus the explanation as to why they are afferent. 



GENERAL AND OSTEOPATHIC. 279 

2. Multipolar cells. Two subdivisions of this type of nerve 
cell are known: 

(a) Those neurons whose cell body is developed within the 
middle layer of the primitive spinal cord and which as the cord 
develops migrate to the anterior horn of the gray matter of the 
cord and become the cell bodies of the somatic efferents or motor 
neurons. Many other cells developed in a similar way from 
neuroblasts formed in the middle layer of the primitive cord and 
brain are the forerunners of other neurons of this type. Their 
dendrites are usually several in number and form receptive sur- 
faces for many afferent fibers. These neurons are sometimes 
known as the Golgi first-type cells. The axones from these cells 
extend peripherally from the cell bodies in the gray matter. These 
neurons are of many different subdivisions according to their 
mode of distribution of their axones and dendrites. They con- 
stitute the anterior horn cells which give rise to the somatic effer- 
ent or motor neurons, the pyramidal cells of the cerebral cortex, 
and the Purkinje cells of the cerebellum. 

(b) The other neurons, the Golgi second-type cells, are 
also developed from neuroblasts of the middle layer of the cord 
but do not migrate to any particular part of it, nor do their pro- 
cesses extend beyond the gray matter of the cord. These neurons 
differ structurally from subdivision (a) of this type in that their 
axones, instead of extending for long distances in the white matter 
of the cord as the spinal nerves, divide into many parts and are 
distributed in the gray matter only. Since these cells also have 
numerous branching dendrites and since none of the cell processes 
extend out of the gray matter, it would seem that the chief func- 
tion of these neurons is that of association of the afferent and 
efferent systems. They serve to connect the afferent of one side 
with the efferent of the same side, and by way of the commissural 
neurons those which extend from the gray matter of one side 
to the gray matter of the opposite side serve to connect the affer- 
ent and efferent of opposite sides of the cord. These cells are 
fewer in number than sub-group (a) of this type, but are of very 
great value as association neurons, serving to associate the ter- 



280 physiology: 

minations of the afferent neurons, of the bipolar cells with the 
efferent neurons described above. These neurons may be said 
to constitute the chief part of the synaptic nervous system. 

Source of Nerve Energy. — It is generally considered that 
the nerve cell is the source of energy for the transmission of im- 
pulses and for determining the functions as well as the nutrition 
of its processes. The cell, then, may be considered as the dynamic 
as well as the trophic center of the neuron. The true source of 
this energy is the chemical changes which occur in the nerve cell, 
in the same way that chemical changes in other tissues furnish 
their source of energy. As evidence of the statement that 
nerve energy is due to its own metabolic changes we offer the 
following: 1. It is generally believed that nerve cells become 
fatigued after excessive activity, as other cells the energy of which 
is known to depend upon chemical changes occurring during their 
acitvity. It has been conclusively shown, for example, that 
the functional activity of muscle tissue depends upon the 
metabolic changes which occur within and about the muscle cells. 
The natural demand of sleep after mental work or emotional 
exercises seems to be necessary for recuperation, just as rest of 
muscle tissue is necessary for its recuperation; 2. If a quantity 
of blood be lost by hemorrhage or otherwise there is also this 
decreased nerve energy, which may be shown by the reduced 
power of mental activity as well as the decreased nerve force in 
the maintenance of normal tissue functions. This is an exact 
parallel of the conditions resulting in other tissues from the loss of 
blood, i. e., a loss of blood is always followed by a decrease in the 
power to function, and the loss of function varies directly with 
the loss of blood in nerve tissue as well as all other tissue; 3. 
It has been shown by experiments with the ergograph that the 
fatigue of the neuro-muscular apparatus also extends to the nerve 
cell and reduces its power to function; 4. The fact that mental 
and other work involving the nerve cell is almost impossible after 
excessive muscular exercise seems to bear out the above mentioned 
findings in the experiments with the ergograph, and further shows 
that the same fatigue which affects the neuro-muscular apparatus 
extends to and involves the higher centers of the brain and cord. 



GENERAL AND OSTEOPATHIC. 281 

Mental energy, therefore, depends upon the same physio- 
logical conditions which determine other kinds of body energy, 
and while within reasonable limits all forms of body energy may 
be thought of as being constant, most certainly we cannot make 
the statement that nerve tissue is non-fatiguable while all other 
tissues are fatiguable. 

Most tissues of the body (possibly all) are in a state of con- 
stant activity during life. This activity may vary greatly at 
different times according to the demands of function of different 
parts of the body and of the body as a whole. During sleep, for 
example, there is very little activity of the cells of striated muscle, 
but the cells of smooth muscle must maintain a certain amount 
of tone to continue their function, such as the demands of peris- 
taltic action, and the required tone of smooth muscle of the arteries 
that proper blood pressure may be maintained, etc. All tis- 
sues are, therefore, capable of a certain amount of work without 
becoming fatigued, as their energy is constantly being restored. 
The continuous activities of the muscles of the heart and the 
muscles of respiration offer examples of this, but there is a limit 
to the amount of work which can be done by any tissue without 
fatigue, and we believe that nerve tissue offers no exception to 
this general law. 

There is good experimental evidence to show (Mosso) that 
mental activity is followed by an increase of temperature of the 
brain tissue, just as an increase of temperature results from 
increased functional activity of other tissues. This, if true, 
would furnish evidence of what most physiologists believe to be 
a fact, namely, that mental work is the result of physical or chemi- 
cal changes, or both, just the same as other body functions are 
explained. There is also other evidence of chemical changes in 
nerve tissue during activity and " Obvious histological changes 
which imply, of course, a change in chemical structure, have 
been observed by a number of investigators. All seem to 
agree that activity of the tissue, whether normal or induced by 
artificial stimulation, may cause visible changes in the appearance 
of the cell and its nucleus. " (Howell.) 



282 PHYSIOLOGY : 

In addition to this evidence of changes occurring in nerve 
tissue during activity of the same we may refer to the fact, as 
stated in a previous chapter, that there is a brief interval of time 
after stimulation during which the nerve cannot be restimulated. 
This is known as the refractory period, and while it is very short 
(about .003 sec), it still shows that the nerve cell is not capable 
of sending out stimuli continuously and without time for chemical 
changes to occur within its substance. Some, the somatic and 
visceral efferent nerve cells, are known to send out stimuli rhyth- 
mically, and we may assume that the rhythmical action of these 
cells depends upon the refractory period. The efferent cells of 
the brain cortex also seem to have the power of sending out im- 
pulses at somewhat regular intervals, but this may vary between 
certain limits, probably not less than thirty and not more than a 
hundred stimuli per second. 

Summation of Stimuli. — It has been shown that if the 
nerve supply to a muscle be stimulated and quickly followed by 
a second stimulus, the application of the second stimulus produces 
a greater amount of contraction than the first. Furthermore, 
if a series of stimuli be applied to the muscle rapidly the contrac- 
tion is markedly increased. This is explained by "the summation 
of the stimuli, " i. e., the second contraction occurring in addition 
to and before the effects of the first are lost. It does not seem 
probable that summation effects could occur in nerve tissue, as 
it does in muscle tissue, but it seems more probable that each 
impulse or unit of function is separate and independent. 



CHAPTER XXXII. 
NERVE REFLEXES. 

Definition. — Nerve reflex may be defined as that involuntary 
response to afferent stimulation caused by efferent functional 
activity. The afferent stimulation causative of these functions 
may come into the cord or brain from many different sources and 
may consist of a great many stimuli functionally different in 
nature. Reflexes vary in nature because of the nature of the 
exciting stimulus, the kind of afferent fibers by way of which 
the impulse is carried, the strength of the exciting stimulus, the 
kind of centers involved in the cord or brain, and many other 
conditions, which are to be considered later. 

Reflex Mechanism. — In every reflex act the involvment 
of the following structures occurs: 1. The sensory or receptive 
surface, from which the stimulus arises; 2. The afferent con- 
ductor (sensory nerve), which carries the stimulus to the centers 
in the cord or brain; 3. The synapse, the central connecting 
system by means of which the stimulus is transmitted to 4. The 
efferent conductor (motor nerve), which conveys the stimulus 
to the 5. Effector, such as a muscle, which is made to func- 
tion as the result of the stimulus. Since nerve stimulus arises 
from without the cord or brain (there is little or no evidence 
to show that nerve stimulus arises spontaneously in the brain 
or cord), these five structural parts are necessary to all kinds 
of normal reflexes. 

The sensory or receptive surfaces may be of many different 
kinds. The skin, which contains many functionally different 
receptive areas such as those which give rise to pain, pressure, 
temperature, and other sensations, constitutes one of the most 
important of the receptive areas. The mucous surfaces likewise 

283 



284 physiology: 

have the power of originating many stimuli, the effects of which 
are widely different in nature. Afferent endings capable of re- 
ceiving and transmitting stimuli which are specific in nature are 
found in many other structures such as the muscles and joint 
surfaces, as well as the end organs of the special sense organs. 

All afferent fibers serve the function of afferent conductors. 
The stimulus going into the cord or brain normally by way of 
these fibers serves to stimulate the cells of the gray matter suffi- 
ciently to maintain a normal "tone" in the structures supplied 
by the efferent neurons. As evidence of this it may be shown: 
1. That the cutting of the posterior roots of certain segments 
of the cord reduces the tone of the muscles supplied by efferent 
fibers from these segments; 2. Stimulation of the central end 
of afferent or mixed nerve trunks increases the tone of the muscles 
supplied from the segments which give rise to the nerve trunk 
stimulated. There is also an increased functional activity of 
the structures of the abdominal, and thoracic viscera, as a result 
of the reflex stimulation; 3. Section of the cord above a certain 
segment allows an increase in the reflex activities of structures 
supplied by nerves orginating below the point of section. This 
increased reflex activity is due to the cutting off of the inhibitory 
functions of the descending neuron. 

The synaptic connection within the cord or brain substance 
is also to be considered as an important part of the reflex mecha- 
nism, since the nature and function of this connecting mechanism 
determines the transmission of the afferent impulse to the efferent 
conductors. The reader is urged to read the physiology of the 
synapse and the experimental work given in Series No. 10. (See 
index.) 

The efferent conductors are of two general kinds, viz., spinal 
and autonomic. These two groups may further be divided into 
many different subgroups according to the kind of structure 
supplied and the functions caused by their stimulation. (See 
classification of nerve fibers, Chapter XXXI.) 

The fifth factor involved in reflex, the effector, is of course 
that which determines the function which is to result from the 






GENERAL AND OSTEOPATHIC. 285 

reflex action. Effectors are of many different kinds, such as 
striated muscle, smooth muscle, secreting glands, etc. The 
effect of the reflex action on these structures may be either stimu- 
latory, i. e., it may be of such a nature that the function of the 
structure is increased, or it may be inhibitory in action, reducing 
the function of the structures involved. In many of the co- 
ordinated reflexes both inhibitory and stimulatory effects may be 
noted on different structures involved in the reflex act. In case 
of the reflex, flexion of the arm for example, it becomes necessary 
to inhibit the tone of the extensor muscles while the flexor muscles 
are stimulated and made to contract. 

The Reflex Arc. — Since all reflex actions result from the 
passage of a stimulus through certain nerve centers, a reflex arc 
must consist of at least two structures, i. e., an afferent conductor 
and an efferent conductor. In Fig. 24 this is shown by the 
afferent or sensory fiber entering the posterior root, its axon termi- 
nating about the dendrites of the anterior horn cell, whose axon 
extends to some peripheral structure. These two structures, the 
afferent and efferent elements, constitute the simplest form of a 
reflex arc. This explains the mechanism according to the neuron 
doctrine, and this mechanism answers in a simple way for the 
central association; but while this plan of transmission is known 
to actually exist in certain lower forms of animal life, it is doubtful 
if such simple association actually exists in the higher forms. 
The reflex mechanism of the higher forms is to be given later. 

Methods of Study. — To study these reflex actions it is well 
to use some lower form of animal life like the frog. In order to 
determine the changes reflex in nature which affect the neuro- 
muscular mechanism, the frog's brain is destroyed by cutting 
the head from the animal's body. It is advisable to pith the 
upper segments of the cord with a probe after the head has been 
removed. Such an animal is known as "a reflex frog." Frogs 
so operated may suffer from shock (see spinal shock) , but this is 
only for a short time, after which the cord reflexes will react nor- 
mally. Animals thus prepared serve the purpose of reflex study 
much better than those which have not had their brains removed, 



286 physiology: 

because in the latter the reflexes are much more complex and 
therefore more difficult to study. 

The fact that reflex activities can be shown to occur after 
the brain has been sectioned from the cord is evidence of the exist- 
ence of reflex centers in the cord. That reflex centers exist in 
various parts of the brain may be shown in a similar way by expos- 
ing the brain and making sections beginning at the anterior portion 
and sectioning backwards until that part of the brain has been 
reached which controls a certain function. As soon as this point 
is reached the function in question will be destroyed. The reflex 
centers in the medulla, such as the respiratory center, the vaso- 
motor center and others, may be located in the same way. 

Specificity of Reflex Action. — Many afferent fibers are 
specific in their reflex function, i. e., they produce or increase the 
functions of only certain structures. An example of this has 
been given in the pressor and depressor fibers, which reflexly 
regulate blood pressure. (See Chapter VI.) Other specific 
afferent reflex fibers, such as those causing or regulating the secre- 
tion of the various glands, are known to exist, but the specificity 
*of reflex function does not depend wholly upon the nature or 
kind of afferent fibers involved in the reflex act. 

The nature of the results of reflex action are determined by 
different conditions, as follows: 1. The nature of the stimulating 
medium and the intensity of its application. Light, for example, 
is the only stimulus which can normally influence the function of 
the retina, and the intensity of the light determines the amount 
of reflex changes which result from the stimulus; 2. The nature 
of the receptive surface or end organ. Many receptive surfaces 
are susceptible to only certain kinds of stimuli, as in the example 
just given of the light on the retina, but this specificness in recep- 
tive function is not at all confined to the so-called special sense 
organs. Most viscera, for example, are not sensitive to handling 
or cutting, but their linings are highly sensitive to foreign sub- 
stances. There would be little or no pain result from operating 
on the ureters or gall bladder, but the presence of renal calculi 
or gall stones is always causative of pain; 3. It has never been 



GENERAL AND OSTEOPATHIC. 



287 



definitely established that the nature of the impulse depends in 
any way upon the structure of the nerve fibers involved in the 
conduction, therefore it is not known that the specific nature of 
the reflex action is in any way dependent upon any structural 
difference in the afferent or efferent conductors; 4. The nature 
of the synapse, its location in the cord or brain, that is, the centers 
in the cord or brain involved, also play important parts in the 
determination of the nature of the reflex action. For the osteo- 
pathic consideration of the influence of conditions of the synaptic 
system on reflex activities, see Part II; 5. The end organ in 

nearly all cases is that part of 
the reflex mechanism which 
has most to do with the de- 
termination of the nature of 
the reflex action. 

Kinds of Reflexes. — 1. 
The simple reflex movements 
are effected by means of the 
simple reflex mechanism as 
shown in Fig. 24. As stated 
above, this mechanism is not 
common to the higher forms 
of animal life. "A simple re- 
flex is probably a purely 
abstract conception, because 
all parts of the nervous system 
are connected together and 
no part of it is probably ever 
capable of reaction without 
affecting and being affected by various other parts, and it is a 
system certainly never absolutely at rest. But the simple 
reflex is a convenient, if not a probable, fiction. Reflexes are 
of various degrees of complexity, and it is helpful in analyzing 
complex reflexes to separate from them reflex components 
which we may consider apart and therefore treat as though 
they were simple reflexes." (Sherrington.) Reflex activities 




Fig. 24 — This figure shows a simple reflex. 
The afferent or sensory fiber with its ganglion 
on the posterior root enters by way of the post- 
erior root and its axon terminates about the 
dendrites of the cell of the anterior horn. 
Such a mechanism serves to illustrate the 
simple reflex but as 'stated elsewhere, probably 
does not exist in the higher forms of animals. 



288 



physiology: 



resulting from simple reflex action affect only a single muscle. 
As an example of a simple reflex the movement of the eye in 
winking may be given, as this is usually only a contraction of the 

orbicularis palpebrarum. 

2. The co-ordinated reflex 
actions differ from simple re- 
flexes in that several muscles 
or groups of muscles are in- 
volved, the central connec- 
tions are more complex (see 
Figs. 25 and 26), the functions 
of the muscles involved are so 
regulated and graduated that 
purposeful, useful, and orderly 
body movements result. 
These reflexes may be obtained 
in the reflex frog by applying 
stimulus to the skin surfaces. 
If the skin is removed or if it 
is in some way protected so 
that the stimulations cannot 
be uniformly applied, these 
results are not obtainable. 
Artificial methods of stimula- 
tion are never entirely satis- 
factory and the results obtain- 
ed from such methods are 
often valueless and resemble 
the convulsive rather than the 
co-ordinated type of reflex 
action. " Adaptation has 
evolved a mechanism for 
which one kind of stimulus is the appropriate, that is, the 
adequate stimulus: other stimuli than the adequate not being 
what the adaptation fitted the mechanism for, or at a dis- 
advantage. Electrical stimuli are in most cases far the most 




Fig. 25. — This figure shows the mechan- 
ism of a complex reflex arc. b. is the afferent 
neuron entering the cord. a. is the associating 
neuron in the cord. c. represents the associa- 
tion of the intermediate neuron with the 
efferent neurones. (Taken from Brubaker, 
after Kolliker.) 



Q H 




O 



pq 



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o 



u 



SO 



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o.ti 



GENERAL AND OSTEOPATHIC. 291 

convenient to use for experimental work, because of their easy 
control, especially in regard to intensity and time. But electrical 
stimuli not being of common occurrence in nature, there has been 
no chance for adaptation to evolve in the organism receptors 
appropriate for such stimuli. Therefore we may say that electri- 
city never constitutes the adequate stimulus, for any receptor, 
since it is always an artificial form of stimulus, and every 
adequate stimulus must obviously be a natural form of stimu- 
lation. " (Sherrington.) 

The fact that the skin surface is necessary for co-ordinated 
movements shows that the receptor surfaces of the afferent portion 
is a very essential part of the reflex mechanism. It has been shown 
that stimuli originating from the external surfaces cause reflex 
movements of the striated musculature and that stimuli origi- 
nating from the interior, such as the mucous surfaces of the viscera, 
cause reflex movements of the smooth musculature. This, how- 
ever, is not a constant rule, as external stimulation may in some 
instances affect internal reflexes. 

By pinching the foot of a reflex frog the foot will be drawn 
away, or by applying a stimulus to the ventral surface the feet 
will be brought around in such a way as if to remove some foreign 
body, which would seem to show purposeful movements in both 
cases. The exactness of these purposeful reflex movements 
shows beyond question that the brain has little or nothing to do 
with the ordinary co-ordinated reflex movements. The centers 
in the cord, therefore, probably function in the unconscious re- 
flexes. It may be that in the lower forms of animal life the spinal 
cord governs nearly all of the visceral as well as the striated 
muscular reflexes and that the brain, if such it may be called, is 
only a complex reflex center, which perhaps regulates some of 
the more complex reflex movements. 

The co-ordinated reflexes are often so purposeful in nature 
when the brainless animal is carefully stimulated that it would 
seem that such movements are actually directed by intelligence. 
This is not the case. It is only the result of a highly developed 
automaton, purely mechanical in nature, which in answer to the 



292 



PHYSIOLOGY 



DORSAL 




VEMTKAL 



Fig. 28. — Showing afferent fibers entering the posterior horn of the cord, and the cell 
bodies and commissural fibers in the gray matter. The fibers entering the gray matter from 
the white matter are also shown. The right side shows the cell bodies and their distribution 
from the gray matter and the left side shows the entering fibers. 

On the right side: 1. represents two motor fibers, one being the anterior horn cell whose 
axon is distributed to striated musculature (somatic efferent), and in the other the cell body 
lies in the antero-lateral part of the gray matter, its axon being distributed to smooth muscle 
(visceral efferent) . 2. Cells of the gray matter, the axones of which pass to the white matter 
of the lateral columns. 3. Cell bodies whose axones pass to the opposite side by way of the 
posterior commissure. These neurones serve to connect the incoming fibers with the opposite 
side of the cord. 4. Golgi cells of the second type, whose short branching axones associate 
the different cells of the same side. 5. Cells whose axones pass to the white matter and help 
to form the posterior columns. 

On the left side: 1. Fibers of the posterior root entering the gray matter of the cord. 
These fibers are, according to their distribution: (a) fibers which terminate in the posterior 
column (zone of Lissauer) of the gray matter and terminate about tract cells, (b) Fibers which 
terminate in the gray matter about tract cells whose axones go to the white matter of the same 
side, (c) Fibers which terminate in gray matter about cells whose axones go to opposite side 
(commissural), (d) Fibers which terminate about motor cells of the anterior horn, somatic 
and visceral efferents. These connections form the simple reflex, but it may be that inter- 
mediate fibers (Golgi cells of the second type) serve to make the connections, (e) Fibers which 
terminate about cells in the dorsal nucleus (Clark's column), (f) Fibers which terminate 
about cells whose axones go to the medulla, (g) Fibers which terminate about cells whose 
axones go to the opposite side by way of the posterior commissure, (h) Fibers which termi- 
nate about Golgi cells of the second type, (i) Fibers whose axones extend upwards in the 
posterior columns. 2. Fibers entering the gray matter from the lateral columns. 3. Fibers 
entering the gray matter from the descending pyramidal tracts and terminating about the 
efferent motor cells of the anterior horn. (Howell, after Lenhosseck.) 



GENERAL AND OSTEOPATHIC. 293 

law of the demand of function has been developed for its own 
protection. It should be remembered that, phylogenetically 
speaking, the spinal cord greatly antedates the brain and that 
the cord's primitive function was that of regulating by reflex 
the various functional demands of the living organism. The 
brain and medulla may be considered in the more highly cephalized 
animals as highly differentiated and complex reflex centers and 
represent the maximum of nerve center development. Develop- 
mentally the brain has come from the cord and not the cord from 
the brain, as might be supposed. 

3. Inco-ordinated, convulsive, or spasmodic reflexes differ 
from the above in that the muscles involved are thrown into 
spasmodic contraction with no order or regularity of movement. 
A single muscle, several muscles, or the entire musculature of the 
body may be involved. Spasmodic reflexes result from (a) an 
excessive sensory stimulation which causes a reflex response as a 
result of an "overflow of stimulus" affecting the neuro-muscular 
apparatus; (b) spasmodic reflexes may also result from an in- 
creased irritability of the nervous system as an effect of some 
toxic substance such as certain drugs, bacterial toxins, toxins of 
perverted metabolism, etc. This may be shown by injecting 
strychnia subcutaneously into a frog. After a few minutes the 
animal is much more susceptible to reflex stimulation and after 
a time the movements become convulsive. The cause of this 
hyper-irritability is most likely the accumulation of toxic sub- 
stances about the cell bodies of the central nervous system, in- 
creasing their sensitiveness to stimuli. "The explanation usually 
given for this result is that strychnin, acting upon some part of 
the nerve cells, increases greatly their irritability, so that when 
a stimulus is sent into the central nervous system along any sen- 
sory path from the skin it apparently radiates throughout the 
cord and acts upon all the motor cells. This latter supposition 
leads to the interesting conclusion that all the various motor 
neurons of the cord must be in physiological connection, either 
direct or indirect, with all the neurons supplying the cutaneous 
surface." (Howell.) This is probably the explanation of con- 



294 



PHYSIOLOGY : 



vulsions and other hyper-irritable nervous conditions which occur 
in certain infectious diseases, such as tetanus, hydrophobia, typhoid 
fever, etc. It is known that hyper-irritable conditions may result 
from osteopathic lesions, which we believe may be explained by 
assuming that these conditions are due to a summation of stimuli 
caused by the irritation produced by the lesion. The reader 
is referred to the chapter on the theories of the osteopathic lesion 
in Part II. 




Fig. 29 — (Courtesy of Dr. Burns.) "The fiber 'A' is viscero-sensory. The body of the 
cell is in the sensory ganglion 'H'. The peripheral prolongation, properly called a dendrite, 
is medullated. It passes through the sympathetic ganglion 'F' without making any physio- 
logical connection with the sympathetic neurons. These fibers retain their medullary sheaths 
until they reach the neighborhood of their termination in the viscera. 'B' is a viscero-motor 
fiber, the axon of a cell in the lateral horn 'O' of the spinal cord. These fibers form the greater 
part of the white rami communicantes, and they usually pass through one or more ganglia 
before forming a synapsis with sympathetic neurons. These fibers are medullated until they 
reach the ganglion of their termination. 'C is a viscero-motor fiber, the axon of a cell in tbe 
sympathetic ganglion 'F'. These fibers are not medullated, usually, and the medullary sheath 
is extremely thin in the very few instances where it is found at all. Impulses carried over 
these fibers are derived from the lateral horn. 

"The lateral horn of the spinal cord 'O' should be considered as part of the autonomic 
nervous system, of which the sympathetic nerves also are a part. The nerve cells of the lateral 
horn of the cord are smaller than those of the anterior horn, and the axones of these cells are 
finer. The axones terminate by forming synapses with sympathetic neurons. The cells of 
the lateral horn of the cord receive impulses from several sources — from cells in the posterior 
horn 'K', from cells of the spinal ganglion 'H\ by collaterals from their axons *L\ from the 
red nucleus by way of the rubro-spinal tract 'X', from the vasomotor and other centers of 
the medulla, and perhaps from other sources. Impulses are carried to the lateral horn only 
from sensory nerves aDQ from centers which co-ordinate sensory impulses. " 



GENERAL AND OSTEOPATHIC. 295 

Reflex Paths. — In explanation of the co-ordinated reflexes 
it is generally assumed that the sensory impulses when they reach 
the cord or brain centers find a certain motor path of. conduction 
to offer less resistance, and therefore pass out by way of this path. 
It ma}^ be further assumed that these pathways correspond to 
certain structural relations within the synaptic portion of the 
central nervous system, which explains why the impulses should 
follow certain paths and why certain reflex actions should result 
from certain kinds of stimulation and from stimuli reaching the 
central nervous system by way of certain nerve trunks. There 
is yet another factor, and that is the fact that these reflex pathways 
can be developed. By constant and continual usage of a certain 
set of muscles in answer to a certain need or afferent stimulation, 
such as the development of the use of the right hand in left-handed 
individuals which may after a time become the easier and more 
natural way and the individual may actually learn to use his 
muscles reflexly in this manner. The explanation of such a change 
seems to be the development of new paths of least resistance. 
Since these long continued practices often develop habit move- 
ments, the term " habit paths" has been given to those reflex 
transfer paths which, because after long practice they offer the 
path of least resistance to certain kinds of stimuli, which in turn 
results in the development of new reflexes. 

The development of habit paths does not necessarily follow 
only the purposeful attempts to use another set of muscles than 
the ones structurally intended for the purpose, but may come 
as a result of continual usage of any set of muscles and is often 
if not nearly always unconscious after long and constant applic- 
tion. So much of our daily work, especially if one is doing work 
which is more or less of a routine nature, is a result of co-ordinated 
reflexes movements that after careful observation of one's own 
actions, he will be forced to admit that a great number of his 
movements are purely reflex in nature and comparatively very 
few are volitional. 

Reflex Animals. — The term reflex animal or spinal animal 
may be applied to any one of the higher animals like the cat, 



296 PHYSIOLOGY : 

dog, monkey, etc., which has had its brain sectioned from the 
spinal cord for the purpose of reflex study. Sherrington and 
others have successively shown that the brain may be sectioned 
from the cord and after time has been allowed for the animal 
to recover from the spinal shock it will show many interesting 
reflexes when the proper receptive surfaces are stimulated. When 
the skin of the ventral surfaces is stimulated the animal will bring 
its feet to the point of stimulation and perform movements as if 
it were voluntarily trying to scratch the surface stimulated. This 
is known as the " scratch reflex." 

If the cord be carefully sectioned in the dorsal region the 
animal may be kept alive for months, and the stimulation of 
certain definite areas supplied by nerves originating from cord 
segments below the sectioned region will be followed by specific 
muscular movements; and in most cases the deep reflexes, such 
as the knee-jerk, also remain active. There is no degenera- 
tion of muscle or other tissue as the result of the section. It has 
been shown (Deason and Robb, and others) that complete section 
of the cord may be made in the cervical region below the origin of 
the phrenics and, if the operation be properly and carefully done, 
the animal may be kept alive for long periods of time and the 
reflexes obtained from segments of the cord below the section may 
remain active. 

In the higher animals the reflex movements are neither so 
easily obtained nor so specific in co-ordination of purposeful 
movements as in the lower animals, such as the frog, because the 
higher animals are less dependent upon the cord and also because 
there is a much higher degree of development of the brain centers 
and the brain, therefore, has more to do with the regulation of 
reflex movements in the higher animals. In monkeys the re- 
flexes in the apinal animal (after section of cord) are much less 
marked than in animals like the dog and cat. According to the 
degree of development the reflexes in the monkey after section 
of the cord are less marked than in the dog, and the reflexes in 
the latter are less marked than in the frog. In the human, as 
has been determined from clinical cases in which the cord has 



GENERAL AND OSTEOPATHIC. 297 

been accidentally transsected, the reflexes, both cutaneous and 
deep, are quickly lost and the musculature is said to lose its tone 
and degenerate. 

It would seem from these facts that some general laws may 
be stated, as follows : 1 . The independence of the cord in regula- 
ting reflex actions varies inversely with phylogenetic development ; 
2. The trophic influences exerted upon structures depend upon 
the perfect integritive functions of the cord to a greater extent 
in the higher forms of life than in the lower. 

Osteopathic Significance. — From an osteopathic viewpoint 
these facts are of much significance. It is considered by some 
who have had little or no actual experience in the study of the 
osteopathic lesion experimentally that the first of these two prin- 
ciples (viz., that reflexes can be obtained in animals lower in the 
scale of development than man, but cannot be obtained in man) 
would tend to discredit the value of mammalian osteopathic 
research work, but these individuals are basing their claims wholly 
upon suppositions and entirely overlook the second of these two 
principles, viz., that minor lesions in animals might produce 
only very slight or possibly no discoverable change, whereas 
similar lesions in the anthropoid ape or the human would produce 
very marked functional disturbances as a result of the disturbance 
of the reflex integrity. As evidence of this we refer the reader 
to Series No. 12 in Part II, in which we have conclusively shown 
that artificial bony lesions in monkeys are followed by symptoms 
very marked in character and quite specific in relation to the 
region of the spine lesioned. We have further shown that marked 
trophic disturbances result from certain spinal lesions in monkeys, 
while similar lesions in dogs seem to produce no- discoverable 
effects. This, then, if the law is to be continued, would show 
that the human is even more susceptible to the effects of minor 
spinal perversions, which involve the physiological integrity of 
the reflex 'mechanism of the cord and its nerve trunks. The 
reader is referred to the chapter on Reflex Action by Dr. Burns, 
to McConnelPs research work, and to our Series Nos. 5, 9, 10, 11 
and 12 in Part II. 



298 physiology: 

Inhibition of Reflex Action. — By the term " reflex inhibi- 
tion" is meant the depression or complete suppression of reflex 
action, which is caused by certain afferent impulses reaching the 
centers of the central nervous system. If a frog be decerebrated 
and the peripheral end of the exposed spinal cord be stimulated, 
the cord reflexes are markedly decreased or completely inhibited. 
In such cases stimulation of sensory surfaces fails to produce 
reflexes in the neuro-muscular apparatus of the animal. If the 
stimulus or stimulating substance be removed from the end of 
the cord the reflexes may again be obtained by the stimulation 
of sensory surfaces. It is stated elsewhere that one of the prin- 
cipal functions of the centers in the brain is that of exerting an 
inhibitory influence upon the reflex centers in the cord, which 
statement is sustained by the above experimental evidence. It 
may be that there are specific inhibitory fibers distributed from 
brain centers, the function of which is to afford a pathway by 
means of which certain reflexes, such as micturition, defecation, 
ets., may be voluntarily inhibited, but the positive proof of the 
existence of such fibers is lacking. 

Another way in which spinal-cord reflexes are inhibited is 
by the application of strong stimulation to sensory surfaces. If, 
for example, pressure be applied to the upper or lower lip, it will 
often prevent sneezing. A similar inhibition of reflexes may be 
demonstrated by stimulating two or more areas of the skin sur- 
face at the same time, in which the case results are often not so 
marked as those occurring from the stimulation of a single area. 
It is supposed that the stimulation of a second area inhibits the 
reflex effects of the first. 

Reciprocal Inhibition. — The usefulness of such an inhibi- 
tion of reflex action has been shown by Sherrington in what he 
terms " reciprocal inhibition." "In the end-effect of certain 
reflexes, for instance the scratch-reflex, there supervenes on a 
phase of excitatory state a state refractory to excitation — a re- 
fractory phase. This refractory phase is, if we seek to put it 
into the class of physiological phenomena to which it must ob- 
viously belong, a state of inhibition. In the scratch-reflex we 



GENEKAL AND OSTEOPATHIC. 299 

have therefore a reflex in which an external stimulus evokes as its 
end-effect an excitatory phase, succeeded by an inhibitory phase, 
and this succession in this reflex, the stimuli being continued, is re- 
peated many times. If we denote excitation as an end-effect by 
the sign plus ( + ), and inhibition as end-effect by the sign minus 
( — ), such a reflex as the scratch reflex can be termed a reflex of 
double-sign, for it develops excitatory end-effect and then in- 
hibitory end-effect even during the duration of the exciting 
stimulus. " ' (Sherrington.) 

A sensory stimulus which excites motor impulses to a reflex 
muscle or to a group of reflex muscles inhibits the motor im- 
pulses to the corresponding extensor muscles, which makes possible 
the easy movement of the joints. The converse of the above 
rule is also true, viz., that when the extensors are stimulated the 
flexors are inhibited by the same reflex stimulus. This explana- 
tion probably serves to explain how in peristaltic movements of 
the intestine there is a wave of constriction preceded by a wave 
of dilation, the dilation being a result of reciprocal inhibition. 
Many other examples could be given of the physiological useful- 
ness of reciprocal inhibition. 



CHAPTER XXXIII. 

RELATION OF THE SPINAL CORD TO REFLEX 

ACTIONS. 

It must be remembered that the cord antedates the brain in 
its phylogenetic development and that in the lower forms of 
animal life (which have no brain) the cord serves as a reflex transfer 
and thus the nerve centers in the primitive spinal cord serve to 
reflexly adjust the animal to its environment. Since from the 
law of "the demand of function" there is a need for a more highly 
differentiated central nerve mechanism for the regulation of the 
more intricate functions made necessary by evolutionary changes, 
higher and more complex nerve centers are developed to meet 
this demand and thus in the higher forms we have animals with 
brains and complex brain centers. 

In these higher brain centers, then, we find those nerve mech- 
anisms which regulate the more recently acquired functions phylo- 
genetically, e. g., the vasomotor centers for regulating blood 
pressure and velocity, the respiratory center for regulating the 
amount of oxygen according to the needs of the animal, the cardio- 
inhibitory center, the pupillary reflex center, etc., all of which 
structures function only in the homothermous or warm-blooded 
animals. In the poikilothermous or cold-blooded animals, in 
which there is no great need for an accurate regulation of body 
temperature, blood pressure, etc., these higher centers do not 
exist. Phylogenetically we may consider the brain as a physio- 
logical luxury and possessed only by those animals which enjoy 
the functions of much more highly differentiated structures, those 
which enable them to automatically adjust their bodily changes 
more accurately to their environment. 
300 



GENEKAL AND OSTEOPATHIC. 301 

Thus we have seen that the function of the reflex centers 
of the cord and brain is that of enabling the animal to reflexly 
adjust its own body conditions to its environment. Life, accord- 
ing to Spencer, is "The continuous adjustment of internal relations 
to external relations/' and it may readily be seen that there is a 
reason for a great structural complexity in the spinal cord of the 
higher forms of animal life. 

PERVERTED CONDITIONS OF THE CORD WHICH 
INFLUENCE REFLEX ACTION. 

It has been shown in the previous chapter how the spinal cord 
of the higher forms of animal life is more easily influenced than in 
the lower forms, and this rule holds true for the higher forms of 
mammals, i. e., the reflexes of monkeys are much more easily 
affected by perverted structural and physiological conditions than 
in such animals as dogs and cats, and likewise the human cord is 
still more susceptible to such variations. The experimental evi- 
dence of this may be found in Series No. 12, Part II. 

Effects of Osteopathic Lesions. — As evidence of the fact 
that osteopathic lesions influence spinal cord reflexes we may cite 
the reader to the results of the original experimental work of 
Drs. Burns and McConnell, given in Part II. Dr. Burns, in her 
chapter on Reflex Action, very clearly explains the mechanism 
of the physiological disturbances, and Dr. McConnell has deter- 
mined the pathological conditions causative of these physiologi- 
cal perversions. The author, with Dr. Robb and other assistants, 
has further shown that osteopathic lesions materially affect the 
normal cord reflexes, and much work has been done to determine 
the nature of such disturbances. See Series Nos. 5, 7, 9, and 10, 
Part II. 

Many different theories have been advanced to explain how 
bony lesions cause perverted physiological changes. These dif- 
ferent theories will be found discussed in detail in Part II. 

Effects of Drugs. — Certain drugs, such as potassium bromide, 
quinine, strychnin, etc., act like bacterial and other toxins upon 



302 PHYSIOLOGY : 

the cells and synapses in the cord, greatly altering the transmission 
of impulses, and the conduction through the synapse is greatly 
reduced. These facts have been observed clinically and con- 
firmed experimentally. 

NERVE TROPHISM. 

Nerve trophism may be defined as the nutritive regulating 
effect upon tissues which is exerted by the nerve supply. The 
facts that degeneration results in nerve tissue when sectioned 
from the cell body, that tissues degenerate when isolated from 
their nerve supply, and that many other perverted functional 
disturbances result from the different kinds of nerve disorders, 
is evidence of some kind of trophic influence exerted by nerve 
tissue upon the structures which they supply. 

The following perverted physiological conditions have been 
known to result from nerve disorders : (1) Degeneration of muscle 
tissue, (2) decreased functional activity of glandular tissue, (3) 
decreased power of regulation of the vasomotors, (4) decreased 
activity of viscero-motors and inhibitors, (5) decreased resistance 
to bacterial invasion, (6) restricted growth and degeneration of 
bone tissue, (7) degeneration of skin as a result of affections of 
both the afferent and efferent nerve supply, (8) abnormal functions 
of the sweat-secreting glands, and (9) decreased nutrition to the 
appendages of the skin, the nails, hair, etc. 

Trophic Properties of the Cord. — There is conclusive 
clinical and experimental evidence to show that the normal re- 
flexes occurring through the spinal cord are responsible for the 
normal tone of the tissues supplied by the efferent nerves. It is 
also known that this trophic function depends upon the complete 
integrity of the entire reflex mechanism. As evidence of this 
we quote the following from Starling: "After complete section 
of the afferent nerves from any part of the surface of the body 
there should be a tendency to trophic disturbances, such as the 
formation of ulcers, etc. Such ulceration is frequently observed 
in patients suffering from spinal disease. After section of the 



GENERAL AND OSTEOPATHIC. 303 

first division of the fifth nerve ulceration of the cornea is often 
produced. These effects are, however, merely due to the absence 
of the normal protective reactions of the part, and can be prevented 
by scrupulous cleanliness and protection of the apsesthetic part 
from all possible injuries. There are other trophic effects caused 
by nerve lesions which can not be ascribed to the mere absence of 
protective reflexes. Thus inflammation of the posterior root 
ganglia often sets up herpes zoster, or ' shingles,' in the region 
of cutaneous distribution of the corresponding sensory nerve. 
Changes in the skin ('glossy skin'), nails, and hair are often seen 
after irritative injuries of nerves to the part." 

It has been stated elsewhere that section of a nerve trunk 
supplying a certain structure decreases the functional activity 
of that structure and reduces its resistance to infection. Some 
degeneration occurs if the afferent fibers or the receptive surfaces 
are affected as stated above, but the greatest changes occur from 
section of the efferent nerve. It is known also that the synaptic 
part of the cord must function properly in order that the normal 
trophic influences exerted by the efferent fibers may result. 

Trophic Nerves. — It is not known how the nerve supply from 
the cord or brain maintains the normal trophic functions of the 
structures supplied, but that it does effect such an influence has 
been positively demonstrated. It is held by many authorities 
that there are no specific trophic nerve fibers, but that the loss 
of tone in tissues to which the nerve supply has been sectioned 
is due to the decreased activity of the structures. In many in- 
stances this is probably true, but even in these cases the nerve 
is the ultimate cause of the activity and the normal integrity 
of the entire reflex mechanism is responsible for normal structural 
nutrition. 

In a few cases at least, specific metabolic nerve fibers have 
been demonstrated. The nerve supply to the salivary glands 
offers an example of this. The spinal autonomic fibers are speci- 
fically trophic in function; i. e., the stimulation of these fibers 
has been shown to cause the formation of zymogen granules, and 
the cranial autonomic fibers have been demonstrated to control 



304 PHYSIOLOGY : 

the amount of secretion. Similar functions have been demon- 
strated to result in many other glandular tissues. 

As evidence against the value of trophic nerves Starling 
suggests that "it is only during post fcetal life that the activity 
of the skeletal muscles is determined by the motor nerves of the 
cord. Thus they may be developed normally even in the com- 
plete absence of a central nervous system. Whether we are 
justified in assuming the existence of trophic nerves exercising 
an influence on the nutrition of the part they supply, apart from 
any influence on its other functions, the experimental evidence 
before us is not sufficient to decide;" but this theory does not 
consider the facts that in the young nutrition and growth are in- 
fluenced by the secretions of certain ductless glands, such as 
the thymus gland, which soon atrophies, and, were it not for some 
other mechanism assuming these functions we might expect a 
failure in nutrition just as that which does occur when nervous 
disorders develop, or we might better say when the nervous system 
fails to develop and function normally. 

Trophic Nerve Paths. — As stated above, trophic nerves 
have not been demonstrated except in a few instances, but there 
is good reason to believe that the muscles receive their trophic 
influence by way of the motor nerve fibers and that the viscera 
receive their trophic innervation from the efferent autonomics. 
It does not seem necessary that fibers specifically trophic in func- 
tion need be demonstrated to show that such influences are caused 
by these nerves. It is known that many of the visceral efferent 
fibers regulate these specific functions of the structures they supply 
and this function being lacking because of some failure on the 
part of the nerve would mean a perversion of metabolism and 
this, when we consider the entire body as a unit instead of a 
mass of segregated structures, would mean bodily disturbance 
as the result of functional failure on the part of some organ or 
organs. Let us urge again that the student bear in mind that 
every organ in the body bears a certain functional relationship 
with every other organ, and that the nutrition of the body 
depends upon the nutrition of its individual cells. (Starr.) 



GENERAL AND OSTEOPATHIC. 305 

Source of Nerve Energy. — That the nerve energy comes 
from the metabolic changes occurring in the cell has been pointed 
out in previous chapters. It may be considered as, automatic 
and originating within the cord as a result of the food supply fur- 
nished to the cells by the circulating body fluid. As evidence 
of this we have the following: 1. Section of the cord above 
does not destroy the trophic properties of the cord cells; 2. Sec- 
tion of the posterior roots or degeneration of the posterior columns 
is # not in itself always causative of trophic disturbances; 3. Any 
decrease in the normal blood or lymph supply to the cord decreases 
the functional activity of the cells in the cord. The fact that 
the presence of oxygen is necessary for normal nerve conductivity 
and that the presence of C0 2 decreases conductivity has been 
repeatedly demonstrated by laboratory tests. 4. Anything 
which prevents the normal drainage of venous blood or lymph 
from the cord, thus failing to relieve the cells of their products 
of metabolism (wastes)/ reduces the functional activity of the 
nerve cells in the cord. 

As further evidence that an increased blood supply and 
venous drainage increase the functional activity of the nerve 
cells in the cord, the results of Series Nos. 16 and 17 show that 
an increased functional activity of the structures supplied by 
certain nerves results from osteopathic treatment (not massage) 
when applied to the segments of the spine from which the nerve 
supply originates. 

It is known that certain chemical changes take place in nerve 
cells when they function, just as occur in other cells of the body. 
It is also known that there is a slight increase in temperature due 
to these metabolic changes. It has been demonstrated that 
during this metabolic process, which is believed to be responsible 
for the production of energy for the transmission of the impulse, 
oxygen is used and C0 2 and other end products are set free. If, 
now, these end products are not removed they act as toxic agents 
to the nerve cells, and at first probably excessively stimulate 
as other toxins do and finally inhibit the function of the nerve 
cells. 



306 physiology: 

It is known that the afferent nerve supply assists in main- 
taining the functional activity of the nerve cells in the cord, and 
therefore a perfect integrity of the afferent and synaptic systems 
is necessary for normal functional activity of the nerve cells in 
the cord. 

The Osteopathic Significance can readily be seen. Since 
the functional activity of these cells which determine trophic 
influences depends upon the general nutrition of the cord, and 
since the normal nutrition of the cord depends upon its blood 
supply and venous and lymphatic drainage and the integrity of 
its afferent and synaptic systems, it is only natural to inquire 
upon what these conditions depend. Proper adjustment, normal 
movement and normal functions of other structures which in- 
fluence these segments of the cord reflexly, is the answer. 

Cord Functions Automatic or Reflex? — Two general 
views are held relative to the way in which the spinal cord regu- 
lates the functions of the structures supplied by its nerves. One 
theory is that its nerve force is due to automatic physiological 
action and the other is that the energy of the nerve cells of the 
cord is a result of reflex excitation. As evidence of the first view, 
viz., that nerve force originated " spontaneously " in the cord, 
the facts given in the preceding paragraphs may be restated. In 
addition to this it should be mentioned that section of the cord 
above or sectioning of the afferent nerve roots does not completely 
destroy the action of the efferent fibers. 

As evidence of the second theory we have the following: 1. 
Muscular movements are all increased by sensory stimulation, 
such as direct nerve stimulation or the sudden application of heat 
or cold to receptive surfaces; 2. Toxins of bacteria or as a result 
of perverted metabolism, which excite the cord centers to greater 
activity, increase muscular tone; 3. Secretion may be influenced 
reflexly; 4. Drugs which reduce the activity of the sensory end- 
ings reduce consciousness; 5. Mental activities are reduced 
by anything which reduces the activity of the sensory nervous 
system or which interferes with the integrity of the reflexes. Any- 
thing which reduces the sensitiveness of the central nervous system 



GENERAL AND OSTEOPATHIC. 307 

reduces the power of the mental faculties; 6. The fact that 
nowhere in the nervous system is it possible to find an entirely 
isolated neuron would seem to be evidence of the theory that all 
nerve functions are a result of reflex action. 

We may conclude from the above theories and the evidence 
of each that nerve energy is dependent upon, first, the blood supply 
and venous drainage to the nerve cells, which factor is absolutely 
necessary to normal function; and, second, that the excitation 
of these cells to activity depends upon their perfect structural 
and functional relations with the afferent system and the synaptic 
system, which effects the physiological connection of the cells 
in the cord with the afferent system. 

Muscle Tone and Its Relation to the Cord. — Muscle 
tone depends upon the motor nerve supply, as is evidenced by 
the atrophy resulting from the sectioning of the anterior roots, 
etc. Muscle tone also depends upon the afferent nerves and 
their sensory endings and the perfect integrity of all structures 
involved in the complex reflex arc. In the lower animals, and 
to some extent in the higher animals, muscle tone is independent 
of the brain centers. Anything, then, which interferes with the 
afferent and efferent paths or the synaptic nervous system reduces 
muscle tone. 

Effects of Extirpation of the Cord. — It has already been 
seen that the spinal cord exercises a tonic activity by way of its 
nerve trunks upon the various structures of the body and that in 
addition to this the cord centers reflexly perform an essential 
function in the co-ordination of the functions of the different 
structures by virtue of their reflex associations. 

Various research workers have studied the effects of hemi- 
section and complete transection of the cord in various regions, 
but the complete removal of the cord was first successfully prac- 
ticed by Goltz. The cord was first transected in the upper tho- 
racic region and the peripheral portion entirely removed by very 
careful surgical operation. The results were as follows : 1. There 
was a loss of muscular tone and atrophy of all striated muscle 
supplied by nerves originating from the segments removed; 2. 



308 PHYSIOLOGY : 

There was also loss of sensation in these same structures; 3. There 
was at first a loss of the tone of the muscles of the blood vessels, 
but this tone seemed to gradually return; 4. The functions of 
the viscera were materially affected and the vessels of the viscera 
were also affected even in those cases in which the lateral chain 
ganglia, the splanchnic nerves, and the vagi were left intact. 
This fact would conclusively show that, while the autonomic 
system is to some extent independent of the central system, the 
co-ordinative and trophic function of the autonomic fibers depend 
upon the reflex and trophic influences of the cord ; 5. The power 
to preserve normal temperature was decreased. As stated else- 
where, the thermogenic centers are probabl} r located at a higher 
level in the central nervous system, but the results of this experi- 
ment would show that there are probably other secondary centers 
which control temperature regulation located in the various levels 
of the cord; 6. Susceptibility to inflammation and infection was 
increased in the splanchnic areas. This fact offers further evi- 
dence of the trophic influences of these nerves; 7. There was 
reduced power of adaptation to both internal and external changes, 
which fact offers further evidence of the co-ordinative influences 
exerted upon the different structures by the spinal cord; 8. There 
was reduced power of co-ordination, which is claimed by some 
authorities to be in part due to the irregularity of the blood supply 
to the different structures. 

The Spinal Centers. — The reader is referred to the chapter 
on this subject written by Dr. Burns, which is to be found in Part 
II. The results of our research agree so thoroughly with her 
conclusions that we have nothing to add except to substantiate 
her findings. 

The Knee-Jerk. — This term is given to that phenomenon 
which is characterized by the sharp, short forward kick which 
follows the tapping of the patellar ligament below the knee. The 
kick is caused by the quick contraction of the quadriceps femoris 
and is supposed to be the result of a reflex stimulus to the fibers 
of these muscles. The reaction is best obtained when the patient 
sits with the legs hanging freely or has one knee crossed over the 



GENERAL AND OSTEOPATHIC. 309 

other. Since the knee-jerk may be obtained in normal individ- 
uals, it is of much diagnostic value in determining conditions of 
the cord. Any condition which interferes with any' part of the 
reflex arc, retarding the transmission of impulses through the 
arc, decreases the knee-jerk. Any affection, therefore, which 
reduces the normal functions of the spino-muscular lower motor 
neurones or decreases the sensitiveness of the synaptic associa- 
tions in the cord reduces or destroys the knee-jerk if the affection 
involves those segments of the cord from which the nerves arise 
which supply the lower limbs. On the other hand, any affection 
which reduces the functions of the cortico-spinal (upper motor) 
neurones and therefore reduces the inhibitory influences, thus 
allowing the cord reflexes to act excessively, increases the knee- 
jerk. 

The knee-jerk may be augmented if the patient uses some 
of his other voluntary muscles, as in gripping something with 
his hands at the same time the tendon is tapped. Some authors 
have questioned whether this phenomenon is actually a reflex, 
but the weight of evidence seems to be in favor of the view that 
it is. 

There are many other diagnostic reflexes which may be found 
fully described in the various works on diagnosis of nervous disease. 



CHAPTER XXXIV. 
CONDUCTION PATHS OF THE CORD. 

The nerve structures in the cord consist of different series 
of columns of cells and fiber paths and the association and com- 
missural fibers. The student is urged to refer to texts on anatomy 
for the structural arrangements of the fiber paths and cell columns. 
The most important columns of the cord are given in the following 
outline : 

I. Ascending or afferent columns. 
I 1 Posterior columns: 

l 2 Column of Goll, posterior mesial fasciculus, fasciculus 
gracilis. 

I 3 Origin, lower sacral segments. 
2 3 Termination, gracile nucleus. 

I 4 By way of lemniscus to end in, 
2 4 Area of body senses. 
3 3 Location in cord, see anatomy. 
4 3 Functions : 

l 4 Muscle sense, chiefly from voluntary 

muscles, tendons, and joints. 
2 4 Co-ordination. 

3 4 Touch (probably pressure sensations, but 
no pain nor temperature). 
2 2 Column of Burdach, postero-lateral fasciculus, fasci- 
culus cuneatus. 

I 3 Origin, mid-dorsal from posterior root ganglia. 
2 Termination, nucleus cuneatus. 
3 3 Location in cord, see anatomy. 
4 3 Functions : 

l 4 Same as Column of Goll. 
310 



GENERAL AND OSTEOPATHIC. 311 

2 1 Lateral columns: 

l 2 Column of Flechsig, fasciculus cerebello-spinalis, 

direct cerebellar tract. 

I 3 Origin, upper lumbar region. 

2 3 Termination: Most fibers enter the restiform 

body (inferior peduncle) of the cerebellum on 

the same side and terminate in the vermiform 

body of both sides. Some fibers terminate 

in the gray matter of the upper part of the cord. 

3 3 This column consists of fibers from Clark's 

column. 
4 3 Location, see anatomy. 
5 3 Functions : 

Muscle sense, muscle tone, co-ordination; some 
fibers are commissural. 
2 W Column of Gowers, superficial antero-lateral fasci- 
culus. 

I 3 Origin, upper lumbar region, cells of the poster- 
ior horn of the same and opposite sides. 
2 3 Termination: Some fibers terminate in the cord. 
Most fibers pass to both sides of the vermiform 
body by way of the superior peduncle and valve 
of Vieussens. Most of the terminal fibers pass 
to the same side; a few pass to the opposite 
side to the superior corpora quadrigeminal body 
and the optic thalamus. 
3 3 Location, see anatomy. 
4 3 Functions: 

Muscle and joint sense, muscle tone, co-ordi- 
nation, pain, temperature; some fibers are com- 
missural. 
II. Descending or efferent columns. 
I 1 Pyramidal tracts. 

I 2 Crossed pyramidal, lateral descending columns: 

l 3 Origin, pre-Rolandic area of the cerebral cortex. 



GENERAL AND OSTEOPATHIC. 313 

2 3 Termination, gray matter of the anterior horn 
and Clark's column to the fourth sacral segment. 
3 Location, see anatomy. 
4 3 Function : 

Voluntary muscular control. These descend- 
ing axones terminate about cell bodies of the 
anterior horn of the gray matter of the cord and 
function as inhibitors to reflex movements, as 
has been explained in previous chapters. 
2 2 Direct pyramidal, anterior descending column: 

l 3 Origin, Rolandic area of the cerebral cortex. 
2 3 Termination, mid and lower dorsal regions of 
the gray matter of the anterior horn of the 
opposite side. 
3 Location, see anatomy. 
4 3 Function : 

These axones regulate the functional activities 
of the cell bodies of the spino-muscular neurones 
which are located in the gray matter of the 
anterior horn. Their function is chiefly that of 
inhibition, as stated above. 
2 1 Cerebro-cranial tracts. 

These fibers originate from centers in the brain and 
medulla and pass peripherally to the cell bodies of the 
ganglia of the cranial nerves, which are motor in function. 
These axones bear the same relation to the cranial nerves 
that the cortico-spinal neurones, described above, bear 
to the spinal nerves which are distributed from the 
spinal cord. 
III. Association or short segmental columns. 

Characteristics: These fiber paths are both ascending 
and descending and serve to associate the various levels of 
the cord. They originate from tract cells of the gray matter 
of the same and opposite sides, pass up or down one or more 
segments in the white matter, and terminate in the gray 
matter of the same and of the opposite sides. 



314 physiology: 

The phylogenetic history of the species shows (1) the long 
neurones to be a product of higher differentiation, (2) the 
length of the neuron varies directly with the phylogenetic 
development and the development of the individual. It is 
known that the independent activities of the cord vary in- 
versely with the length of its fiber paths. In the higher 
forms of animal life, therefore, the cord is found to be rich 
in these association fibers, giving the animal a greater power 
of co-ordination of functions with the centers in the brain. 
The independence of the organism of its cord varies directly 
as its differentiation. 



CHAPTER XXXV. 
THE CRANIAL NERVES. 

It has been thought best to describe the cranial nerves in 
outline form, and that the student may have access to a source of 
reference, a brief discussion of the anatomy of the nerves is also 
given. The cranial nerves are twelve in number and, with the 
exception of two, the olfactory and optic, they are quite similar 
to the spinal nerves in that they nearly all consist of afferent and 
efferent parts. In those nerves which are afferent in function 
the ganglia of their sensory portion are located irregularly, because 
of the many foldings which have occurred in the development 
of the brain. 

I. The Olfactory Nerve. — 1. Deep origin, limbic lobe and 
optic thalamus; 2. Superficial origin, the olfactory bulb; 3. 
Foramen of exit, cribriform plate of the ethmoid bone; 4. Dis- 
tribution : There are three branches of this nerve, (a) the internal 
branch supplying the septum of the nose, (b) the middle branch 
the superior turbinated bone and the Schneiderian membrane, 
and (c) the outer branch supplying the lateral wall of the nose; 
5. Function, sensation of smell. 

II. The Optic Nerve. — 1. Deep origin, optic thalamus, 
superior quadrigeminal body, and lateral geniculate body; 2. 
Superficial origin, the optic tract; 3. Foramen of exit, optic 
foramen; 4. Distribution, the retina; 5. Function, sensa- 
tion of sight. 

III. The Oculo- Motor Nerve. — 1. Deep origin, fibers 
forming this nerve originate from the gray matter of the aqueduct 
of Sylvius subjacent to the superior quadrigeminal body; 2. 
Superficial origin, on the median side of the crus in front of the 
pons; 3. Foramen of exit, sphenoidal fissure; 4. Distribution, 

315 



316 physiology: 

this nerve supplies the levator palpibrae superioris and all of the 
muscles of the orbit except the superior oblique and the external 
rectus. It also supplies the intrinsic muscles of the eye, viz., the 
circular fibers of the pupil and the ciliary muscles for accomoda- 
tion; 5. Function, somatic and viscero-motor to the muscles sup- 
plied. 

IV. The Trochlear Nerve. — 1. Deep origin, fibers con- 
stituting this nerve arise from the aqueduct of Sylvius in the floor 
of the fourth ventricle at a level with the inferior quadrigeminal 
body and just posterior to the nucleus of the third nerve; 2. 
Superficial origin, at the outer side of the crus just in front of the 
pons. The fiber tracts cross, forming a complete decussation; 
3. Foramen of exit, sphenoidal fissure; 4. Distribution and 
function, fibers from this nerve supply the superior oblique muscle, 
the cavernous plexus, and the lateral sinus. Its functions are 
motor and trophic. 

V. The Trigeminal Nerve. — 1. Deep origin, this nerve 
arises by two parts: (a) The ascending or sensory portion arises 
from the long tract of the medulla, which is continuous below 
with the substantia gelatinosa Rolandi, (b) the descending or 
motor portion arises just internal to the sensory portion in the 
superior mesial part of the floor of the fourth ventricle ; 2. Super- 
ficial origin, in the lateral surface of the pons nearer the upper 
border than the lower; 3. Foramina of exit, (a) the opthalmic 
division emerges through the sphenoidal fissure, (b) the superior 
maxillary division by way of the foramen rotundum, (c) the 
inferior maxillary division by way of the foramen ovale; 4. Dis- 
tribution and function: This nerve is both motor and sensory 
to all the muscles of mastication except the buccinators. Fibers 
from this nerve are sensory (pressure, pain, and temperature) 
to the face, forepart of the scalp, eyes, and nose, a part of the ear, 
the anterior two-thirds of the tongue, and the dura mater. 

VI. The Abducent Nerve. — 1. Deep origin, just be- 
neath the floor of the fourth ventricle; 2. Superficial origin, 
on the dorsal surface of the pons just above the pyramid; 3. 



GENERAL AND OSTEOPATHIC. 317 

Foramen of exit, sphenoidal fissure; 4. Distribution and func- 
tion, fibers of this nerve are motor to the external rectus of the eye. 

VII. The Facial Nerve. — 1. Deep origin, fibers forming 
this nerve arise from the mesial portion of the floor of the fourth 
ventricle, lateral and deep to the nucleus of the sixth nerve and 
internal to the spinal root of the fifth tract; 2. Superficial origin, 
on the posterior margin of the pons lateral to the sixth nerve, 
below the fifth, and internal to the auditory nerve; 3. Foramen 
of exit, through the internal auditory meatus, then through the 
aqueduct of Fallopius in the petrous portion of the temporal 
bone and then through the stylo-mast oid foramen; 4. Distribu- 
tion and function: (a) The motor portion supplies the buccina- 
tor and stapedius muscles; (b) sensory fibers by way of the corda 
tympani pass to the anterior two-thirds of the tongue and con- 
vey specific sensations of taste; (c) autonomic fibers, vaso-dilator 
and secretory, are supplied to the submaxillary and sublingual 
glands by way of the corda tympani branch. This nerve also 
gives branches to the nasal and buccal mucous membranes. 

VIII. The Auditory Nerve. — 1. Deep origin, this nerve 
arises by two divisions, as follows: (a) The cochlear division 
arises from the spiral ganglion of the ventral cochlear nucleus 
and the tuberculum acusticum, (b) the vestibular division arises 
from the auditory nuclei and the striae of the floor of the fourth 
ventricle; 2. Superficial origin, both branches pass out over 
the posterior border of the pons; 3. Foramen of exit, internal 
auditory meatus; 4. Distribution and function, the cochlear 
division supplies the macula acustica of the saccule, ampulla, 
and organs of Corti. The vestibular division supplies the macula 
acustica of the utricle and ampullae of the semicircular canals. 
(See Physiology of the Ear.) 

IX. The Glossopharyngeal Nerve. — 1. Deep origin, 
fibers constituting this nerve arise from the nucleus ambiguus 
and fasciculus solitarius of the floor of the fourth ventricle; 2. 
Superficial origin, fibers constituting the nerve pass out from the 
medulla between the olivary body and the restiform body; 3. 
Foramen of exit, jugular; 4. Distribution and function: (a) 



318 physiology: 

This nerve furnishes motor fibers to the stylo-pharyngeus muscle, 
(b) general sensation to the posterior one-third of the tongue, 
the soft palate, the tonsils, the upper part of the pharynx, the 
Eustachian tube and the tympanic cavity, (c) special sensation 
(sense of taste) to the posterior one-third of the tongue and sur- 
rounding mucous membranes, (d) autonomic fibers, vaso-dilator 
and secretory (nerve of Jacobson) to the parotid glands, and 
vaso-dilator to the tonsils and surrounding vessels. 

X. The Pneumogastric Nerve. — 1. Deep origin, nucleus 
ambiguus and fasciculus solitarius; 2. Superficial origin, just 
in front of the restiform body; 3. Foramen of exit, jugular; 
4. Distribution and function: (a) Somatic motor fibers are dis- 
tributed to the soft palate, pharynx, larynx, and muscles and 
joints of the larynx; (b) viscero-motor fibers are supplied to the 
trachea, bronchi, oesophagus, stomach, and intestines to the 
descending colon, gall bladder, and gall duct, pancreas, and prob- 
ably the liver; (c) viscero-inhibitor fibers are supplied to the 
heart and to the muscles of the gall bladder; (d) vaso-dilator fibers 
are probably supplied to the vessels of the alimentary canal; 
(e) sensory fibers are supplied to the respiratory tract from the 
larynx down, the pharynx, the digestive tract, the pancreas, the 
gall bladder and duct, the liver, the concha of the ear, the internal 
auditory meatus, and meninges. 

XI. The Accessory Nerve.— 1. Deep origin, nucleus 
ambiguus and fasciculus soltarius and extending downward toward 
the sixth cranial nerve in the lateral margin of the horn; 2. Super- 
ficial origin, the accessory part comes out with the fibers of the 
vagus, the spinal part emerging from the lateral aspect of the 
cord below the origin of the tenth nerve; 3. Foramen of exit, 
jugular; 4. Distribution and function, the spinal portion of 
this nerve is motor to the sterno-mastoid and trapezius muscles 
and the accessory portion is distributed with the tenth nerve. 

XII. The Hypoglossal Nerve. — 1. Deep origin, fibers 
constituting this nerve arise from the lower mesial portion of the 
floor of the fourth ventricle and the groove between the olivary 
body and the medulla; 2. Superficial origin, between the olivary 






GENERAL AND OSTEOPATHIC. 319 

body and the pyramid. The two roots unite in the foramen or 
just after leaving it; 3. Foramen of exit, anterior condyloid; 
4. Distribution and function: (a) Sensory recurrent fibers are 
distributed to the meninges of the brain and (b) motor fibers are 
distributed to the intrinsic muscles of the tongue, the thyro-hyoid, 
the genio-hyoid, the hypoglossus and the genio-hyo-glossus muscles. 



CHAPTER XXXVI. 
PHYSIOLOGY OF THE BRAIN. 

It is now generally considered by all physiologists that the 
cortex of the cerebral gray matter is the structural seat of con- 
sciousness. Every part of the cortex receives incoming or afferent 
fibers, which indirectly have come from some peripheral structure. 
The cortex also contains cells, the fibers of which are efferent 
in nature and carry outgoing impulses. Every part of the cor- 
tex is, therefore, an afferent ending and an efferent center, from 
which projection fibers are sent to other parts of the brain and to 
peripheral structure. Every part of the brain cortex may be 
considered as a termination of some afferent path and also as an 
efferent center or origin of some efferent path. 

The Brain a Complex Reflex Center. — Because of its 
numerous afferent and efferent functions, together with its highly 
complex association fibers, which serve to connect various parts 
of the cerebral cortex, the brain cortex may be considered as a 
highly complex reflex center. It is quite definitely decided at 
present that that function which was once considered to be due to 
an automatic or spontaneous nerve action is effected by a highly 
complex reflex mechanism and that there is little, or most probably 
no, such thing as spontaneous or automatic action of the cells 
in the cerebral cortex, and that many of the so-called spontaneous 
actions of the brain, such as inspiration to thought and so on, 
are to be explained by the assumption that these conditions are 
the result of some afferent stimulation to cortical activity. 

The structural nature of the cortex is such that it could be 
fitted only for reflex functions and not for the origination of auto- 
matic actions. There are no isolated neurons in the cortex, 
but all are connected in such a way that they would seem to be 
320 



GENERAL AND OSTEOPATHIC. 



321 



fitted only to function as a reflex system. Any structural differ- 
ences of the cells of the cortex, if such may exist, for the perform- 
ance of such functions as thought, consciousness, and so on, lie 
in the ultimate chemical composition of the individual cells instead 
of any microscopic structural differences. "Since consciousness 
is effected through the intermediation of the cortical neurons, it 




Fig. 31. — This figure shows the projection fibers of the cerebrum and cerebellum and a 
lateral section of the internal capsule. A, represents the tracts from the frontal gyri to the 
pons. The fibers are seen to continue to the cerebellum. This is the anterior cerebro-cortico- 
pontine tract; B, the motor tract from the pre-central area of the cerebral cortex; C, the afferent 
or sensory tract terminating in the area of the body senses; D, the visual tract going to the 
occipital region; E, the auditory tract; F, fibers of the superior peduncle of the cerebellum; G, 
fibers of the middle peduncle uniting with the fibers from the frontal gyri in the pons; H, inferior 
peduncle fibers of the cerebellum; J, fibers extending between the auditory nucleus and the 
inferior corpora ouaclrigeminal body; K, motor decussation; Vt., the fourth ventricle. The 
Roman numerals refer to the cranial nerves. (Modified from Starr.) 



322 PHYSIOLOGY : 

follows that, so far as our present knowledge goes, the physiology of 
the cortical neurons is the physiology of consciousness. " (Burns.) 

Further evidence of this conclusion may be had from a careful 
study of the brains of different animals in their phylogenetic 
development. The greater mental development of the higher 
forms of animals is associated with the greater complexity of their 
neuron connections and does not depend upon any observable 
structural differences in the cells of the cerebral cortex. Since 
the number of cells per cortical area varies inversely with phylo- 
genetic development, or in other words since the same area of 
cortex of certain animals lower in the scale of life than man have a 
comparatively greater number of cells, it may readily be seen 
that the power of mental activity does not depend upon the actual 
number of cells in the cerebral cortex. 

The number of dendritic connections in the cerebral cortex 
of any animal varies directly with its phylogenetic and onto- 
genetic development. From this it may be seen that the Higher 
the animal in the state of development the greater is the complex 
association mechanism between the various centers of its cerebral 
cortex, and that during the development of the individual from 
infancy to maturity there is a constant increase in the complexity 
of its cortical neuron associations. In the higher forms of animal 
life the cortical cells are fewer in number, but the branching is 
greater. The greater mental activity of the higher forms of 
life is therefore considered to depend upon this rich interconnection 
between the various cortical centers, which makes possible a 
complex association of the different centers by way of these inter- 
vening fibers. It is by this means that the individual animal 
high in the scale of life is enabled to better analyze and correlate 
the various impulses that come to its cortex by way of its afferent 
system, and in this way its powers of consciousness are increased 
in proportion to other animals. Animals possessed with these 
powers of association of afferent impulses are better enabled to 
understand conditions of their immediate environment. 

The reader is urged to study the chapter on "The Physiology 
of Consciousness, " by Dr. Burns, in Part II. 






GENERAL AND OSTEOPATHIC. 323 

Effects of Extirpation of the Cerebrum. — In the lower 
animals, such as the frog, for example, the effects of extirpation 
of the cerebrum are very slight. If the cerebrum of ,the frog be 
removed the animal seems to have lost very little of its powers 
to perform normal functions. It can jump, swim, and maintain 
normal equilibrium under normal conditions. If thrown into 
the water it will swim to some floating body, climb upon it, and 
act in every way as a normal frog would act. One thing, however, 
is practically always lost, even in the lower animals after de- 
cerebration, and that is the memory of past experiences. The 
power of instinct is usually lost, which renders the animal unable 
to perform certain functions as others of its kind may do. 

Effects of Decerebration in Higher Animals. — The 
effects of extirpation of the cerebrum seem to vary directly with 
the scale of development. In dogs, for example, the extirpation 
of the cerebrum is usually fatal, and in those cases in which the 
animal does survive from a partial extirpation the results are 
always very marked. If only a portion of the cerebral cortex be 
removed the animal will usually survive, considering that the 
operation has been carefully performed, and after a period of 
weeks or months recovery from the severity of the symptoms 
almost always occurs. After a period of some months or a 
year or two the animal may completely recover and regain practi- 
cally all of its normal functions. The amount of recovery depends, 
of course, upon the extent of the area of the cortex extirpated. 

Pigeons are the animals commonly used for the study of 
decerebration effects, because the operation can easily be done 
and because they offer good opportunities for study. The pigeon 
after recovery from the operation shows many abnormal condi- 
tions, as follows: It is always drowsy and seems to take no in- 
terest in the affairs of its environment. It will stand for hours 
with head drooped, feathers ruffed, wings dropped, and eyes 
closed. Its motor powers seem to be well intact; that is, it has 
the power of movement and perfect regulation of its equilibrium, 
but seems to have no knowledge of approaching dangers, etc. 
If allowed to become hungry it will appear restless and sometimes 



324 PHYSIOLOGY I 

walk impatiently about the cage and will occasionally actually 
pick carelessly at the bars of the cage or at the floor, but there 
seems to be little or no volition involved in this act, as, for example, 
if corn be placed within its reach the dropping of the grains will 
often cause the animal to seemingly try to get the food by picking 
at the floor, but these attempts are never successful in getting 
food into the mouth, as it never actually strikes near the grain. 
The picking, therefore, in such cases is not really regulated by any 
voluntary control. When the animal is fed it is necessary to open 
the mouth, place the grain within the mouth, and force it into the 
oesophagus. Otherwise the animal cannot swallow. It will 
be remembered that the act of swallowing is divided into two 
parts, namely voluntary and reflex, the first of which concerns the 
passage of the bolus through the mouth and pharynx and is there- 
fore under the control of the cerebrum. If the decerebrated 
pigeon be thrown into the air it can usually balance itself and 
fly without difficulty, and can even perch and maintain its equi- 
librium, but seems to have no power to initiate a change of position 
when confronted by conditions of danger, etc. If the decere- 
brated bird be placed upon a table it will often walk impatiently 
about, seemingly trying to find a way to get to the ground, but 
its seems to be unable to understand that it has any use of its 
wings. Such an animal was once known to hop from the table 
onto a box placed near the table and from there to the floor, which 
action would indicate that the animal had exerted some volition 
in the act, but when the animal was replaced upon the table it 
failed to repeat this act, and we must therefore question whether 
the first instance was purposeful. 

Cerebral extirpation in monkeys offers a most excellent oppor- 
tunity for the study of these effects. In the case of one monkey, 
in which the frontal and parietal lobes of the left side were re- 
moved, the animal was observed for a period of eleven years with 
the following results: The character of the animal was entirely 
unchanged and all traits seemed to remain unaltered. There 
was no loss of memory or intelligence, but the movements of 
the right side were affected until the time of death. There seemed 



GENERAL AND OSTEOPATHIC. 325 

to be complete paralysis immediately following the operation, 
from which the animal gradually recovered, and in time it became 
able to use the muscles of its right limbs fairly well, but was al- 
ways somewhat clumsy. The inability of the animal to co-ordinate 
the movements of the muscles of the right side may possibly have 
been due to an interference with the afferent system and its in- 
ability to receive sensory stimuli from the periphery. The animal 
used its right hand and right foot only when it had to do so, but 
learned after a time to put out its right hand for food when the 
left was tied. It would seem, therefore, that there is a possibility 
of the existence of motor fibers from both hemispheres of the 
cortex to the same group of muscles. This, however, could be 
explained by assuming that the functions of the muscles of the 
right side in this case were controlled by association fibers in the 
cord rather than by fibers of a direct descending column. 

LOCALIZATION OF CEREBRAL FUNCTIONS. 

Sensory Areas. — The first valuable work along this line 
was done by Gall, who was the founder of phrenology. He de- 
termined that the cerebral cortex was not only that region which 
served as the structural basis of consciousness, but further assumed 
that various areas had specific functions, such as judgment, in- 
telligence, memory, imitativeness, and a great many others. These 
theories were overthrown by Flourens, who proved Gall's conclu- 
sions to be fallacious, both experimentally and theoretically. 
Flourens concluded that the cerebral hemispheres functioned as 
a whole in the regulation of consciousness, intelligence, and will. 

Modern research workers have found that in general Flourens 
was right and that it is the co-operative functioning of the various 
areas of the cerebrum which determines the consciousness, or in 
fact all psychical conditions, of the individual at all times. Since 
the work of Flourens it has been shown that he was wrong in 
assuming that there are no functionally differentiated areas, and 
many such centers are now quite definitely located. 



326 



physiology: 




GENERAL AND OSTEOPATHIC. 327 

Broca's Area — Center for Speech. — It was shown by 
Broca, a French physician, in 1861 that a certain area, the third 
frontal convolution of the left hemisphere, was constantly asso- 
ciated with aphasia or loss of the power of speech in right-handed 
individuals. It has been so constantly shown since that time that 
pathological lesions of this area are associated with this affection 
that this center has since been known as the area of Broca. Broca, 
however, was not the first discoverer of this center, but only con- 
firmed the findings of two others, viz., Bouillaud and Dax. It has 
since been shown that in left-handed individuals the corresponding 
area of the opposite side is affected in aphasia and that ambi- 
dextrous persons seldom, if ever, suffer from aphasia. 

Kinds of Aphasia. — Since the result of the functioning of 
the different areas of the cerebrum and the correlation of these 
is expressed by speech the study of this function, or rather any 
abnormality of this function, often throws much light upon the 
general functions of the cortex and its various parts. The term 
aphasia is, therefore, a somewhat general term and refers to that 
condition in man which renders him unable to properly interpret 
or express his ideas in speech. Aphasia is generally divided into 
two forms, as follows: 

Motor Aphasia or Broca's Aphasia. — This condition 
was first described by Broca as that in which, although the indi- 
vidual could understand what was said to him, he was unable 
to speak. The pathological lesion causative of this condition, 
as stated by Broca, was to be found in the third left frontal con- 
volution. The general intelligence of the patient is not necessarily 
involved by such lesions. 

Sensory Aphasia or the Aphasia of Wernicke. — In this 
condition the patient's ability to understand spoken words is 
materially reduced or even destroyed, and his general intelli- 
gence is also impaired. The area, lesions of which is responsible 
for this trouble, has been located by Wernicke and is said to cover 
rather a large area of the cortex. It is known as Wernicke's 
area and lies in the supramarginal and angular gyri and the poster- 
ior portion of the first and second temporo-sphenoidal convolu- 




Fig. 33. — Diagram of the Sensory Areas. 1, lateral aspect of hemisphere, primary 
visual area; 2, mesial area of hemisphere, primary visual area; 3, lateral aspect of hemisphere, 
visual overflow; 4, mesial aspect of hemisphere, visual overflow; 5, primary auditory area; 
6, auditory overflow. (Courtesy of Dr. Burns.) 

tions. In case of inextensive lesions of these areas there may 
be only a very limited interference with the power of speech, but 
in the extensive regions there may be total inability of speech with 
severe impairment of the general intelligence. The patient may 
be able to speak, but does not understand what is said to him. 
There are, however, conditions in which the patient suffers both 
from sensory and motor aphasia and in which conditions he can 
neither speak nor understand spoken words. 

Another condition sometimes observed is alexia, or word 
blindness. It is the inability to interpret written or printed 



GENERAL AND OSTEOPATHIC. 



329 



words or phrases. This condition is also known as optical or 
visual aphasia. Another form of aphasia closely associated with 
alexia (possibly the same thing) is musical aphasia or music 
blindness. It is the inability to interpret printed music notes. 
Such individuals can often play well and appreciate music thor- 
oughly but have limited or possibly no power to interpret music 
from the printed sheet. 

Anarthria or aphemia may be said to be another form of 
aphasia in which there is an impairment of the powers of expres- 




Fig. 34. — The Language Centers. 1, Motor area for the muscles concerned in speech; 
2, speech center, for the co-ordination of the movements of the muscles of speech; 3, center for 
the memories of heard words; 4, primary motor for the movements of the fingers, etc.; 5, 
writing center; 6, center for the memories of seen words. (Courtesy of Dr. Burns.) 



330 PHYSIOLOGY : • 

sion, the ability to understand spoken or written words, the in- 
telligence being usually unaffected. This condition has been 
associated with pathological lesions of the white matter of the 
external capsule. 

It may be that these motor functions are controlled by specific 
centers or areas and it has been suggested that other areas, namely, 
the ascending frontal convolutions, in addition to the one above 
mentioned, is concerned in these cerebral processes causative of 
movement, but it is most likely that these complex mechanisms, 
such as speech, depend upon a much more extensive association 
for their neural basis. It is highly probable that a word or phrase 
which expresses an idea involves all or nearly all of the various 
sensory centers in its process of effecting complete understanding. 
It is the power of the individual to associate and correlate the 
results of activities of many or all of these various centers which 
give completeness to the understanding. It has been stated 
that even Brocas' area is not a specific center by any means. " The 
cases described by Broca of motor aphasia are really cases of 
sensory aphasia from lesion of Wernicke's area, combined with 
anarthria due to subcortical injury of the fibers of the internal 
capsule. The statement that there is no loss of intelligence in 
these cases of so-called motor aphasia does not bear investigation. " 
(Starling.) From this it will be seen that those who would des- 
cribe specific areas to any particular function of the cerebral 
cortex have arrived at such conclusions rather hastily, for there 
does not seem to be sufficient clinical and experimental evidence 
to bear out their statements. On the other hand, it would seem 
that in general the functions of the cerebral cortex depend, as 
we have stated in the beginning of this chapter, upon the com- 
pleteness of the dendritic connections and the association of the 
various sensory areas of the cerebral cortex. 

Motor Areas of the Cerebrum. — The localization of the 
motor areas is much less difficult than the localization of the 
sensory areas. In case of the motor areas it is possible by stimu- 
lation of the exposed cortex artificially to determine what muscles 
are involved and thus determine the functions of the regions 



GENERAL AND OSTEOPATHIC. 



331 



stimulated. The results of experimental work done by Shafer, 
Farrier, and others upon dogs, apes, and other animals, and the 
results of surgical work on human individuals have quite definitely 
located the motor areas of the cerebral cortex. "This motor area 
surrounds the central sulcus of Rolando and extends inward upon 
the mesial surface of the cerebrum." By the careful application 




Fig. 35. — Showing the motor areas or' the human brain. (Brubaker, after Mills.) 

of electrical stimulus by means of platinum electrodes the smal- 
ler areas regulating the activities of certain muscles or groups 
of muscles may be accurately located. The results of recent 
work along this line done by Sherrington and others show that 
the motor area is located anterior to the central convolution 
and corresponds to those regions from which the pyramidal tracts 
arise. That this is the location of the motor centers regulating 
the voluntary musculature has been confirmed by the clinical 
experience of many observers, who have studied the pathological 
changes in the brain in cases of muscular paralysis. 



332 physiology: 

Course of the Efferent Motor Fibers. — Impulses from 
these cortical centers, according to Howell, take the following 
course from the cortex : "1, Corona radiata ; 2, internal capsule; 
3, peduncle of the cerebrum; 4, pons varolii, in which they are 
broken into a number of smaller bundles by the fibers of the middle 
peduncle of the cerebellum (brachium pontis). In this region, 
also, some of the fibers cross the mid-line, to end in the motor 
nuclei of the cranial nerves: Third, fourth, fifth, sixth, and sev- 
enth; 5, anterior pyramids; 6, pyramidal decussation; 7, anter- 
ior and lateral pyramidal fasiculi in the cord." These fibers 
terminate about the cell bodies of the somatic efferent neurons 
in the cord or about corresponding cell bodies of the cranial nerves. 
The exact mechanism of the association of the cortico-spinal fibers 
with the spino-muscular fibers is not definitely understood. It 
is believed that in some cases the axons of the cortico-spinal neuron 
may terminate directly in relation with the dendrites or the cell 
bodies of the spino-muscular neurons. They may also terminate 
about intermediate fibers, which serve to associate the cortico- 
spinal neurons with the musculo-spinal neurons. 

It may be seen, therefore, that the nervous mechanism asso- 
ciating the cortex of the brain with the voluntary muscles consists 
of two parts: First, the cortico-spinal neuron, commonly known 
as the upper motor neuron, which carries the message from the 
cells of the cerebral cortex to the motor cells in the cord or to the 
motor cells of the cranial nerves; second, the spino-muscular, 
commonly known as the lower motor neuron, which carries the 
impulses to the muscles supplied. The cortico-spinal system 
seems to exercise an inhibitory function over the cell bodies of 
the lower motor neurons, preventing their excessive activity from 
stimulation by way of reflex from the afferent spinal nerves. The 
functions of these fibers will be illustrated more in detail in another 
chapter, which considers the various symptoms resulting from 
lesions of the different pathways. 



GENEKAL AND OSTEOPATHIC. 



333 



FUNCTIONS OF THE CEREBELLUM. 



Like the cerebrum, the cerebellum is a complex reflex arc, 
it having many nerve connections with the cord and with other 
parts of the brain. It is connected with the cord and the medulla 
by way of the inferior peduncles and receives fibers from the 
following structures: The cerebro-spinal fasciculus, nuclei grac- 
ilis and cuneatus, and Gower's tract, which transmits the deep 

sensibilities from the 
muscles, joints, etc. It 
has connections with 
the vestibular branch of 
the eighth nerve, by 
which it in some way 
seems to be associated 
with co-ordination. It 
also has connections 
with the tenth, fifth, 



optic 



and possibly 
nerves. 

The result of extir- 
pation of the cerebellum 
is total inco-ordination 
and possibly some loss 

F CEREBELLUM f i 1 1 *K'1' + * 

of Woman of About 30 Years. Semi-diagrammatic. 72 01 ine Cieep SenSlDlllLieS, 
diameters. (Courtesy of Dr. Burns.) but there ^ nQ appaj _ 

ent loss of sensations, nor are there any signs of psychic dis- 
turbances. There is very little known positively regarding its 
functions, but the following theories are sustained by experi- 
mental and clinical evidence: 1. Co-ordination of muscular 
movements in locomotion; 2. Center of muscle and joint sense, 
and; 3. It probably has something to do with the augmentation 
of motor activities by way of the pyramidal tracts. 




CHAPTER XXXVII. 

EFFECTS OF PATHOLOGICAL LESIONS OF 
THE SPINAL CORD. 

Upper Motor Neuron Lesions. — The fibers extending from 
the nerve cells of the various brain centers to the various cell 
bodies located in the cord are known as cortico-spinal or upper 
motor neurons. It is the function of these nerve fibers to carry 
impulses from the brain centers to the nerve cells located at various 
levels of the cord. As has been pointed out in previous chapters, 
these fibers exert an inhibitory influence on the cell bodies of the 
cord from which impulses are sent to peripheral structures. 
This fact should be borne in mind in order to understand the 
different symptoms which result from lesions involving these 
fibers. 

Cortico-Spinal Paralysis. — Paralysis resulting from patho- 
logical lesions of the upper motor neuron are characterized by 
certain symptoms which may easily be understood when the 
functions of these fibers are understood. The symptoms of lesions 
of the cortico-spinal neurons are as follows: 

1. The muscles involved in the paralysis are not completely 
paralyzed. This is because the cell bodies in the cord (cells of 
the lower motor neuron) are not entirely shut off from their corti- 
cal connections by such a lesion. It is probable that the lesion 
is not sufficiently extensive to involve all of the descending fibers 
of the cortico-spinal system of one side and, even if this should 
be the case, the descending fibers of the opposite side by their 
crossing at the different levels furnish some stimulus to the cells 
of the cord which supply impulses to the musculature. 

2. All muscles of the part affected by the paralysis are equally 
involved. This, as has been explained above, is due to the exten- 

334 



GENERAL AND OSTEOPATHIC. 335 

sive involvment of many segments of the cord, since the lesion 
affects fibers of the upper motor neuron, which are distributed 
to many segments. 

3. The musculature of the part involved in the paralysis is 
spastic, the joints are stiff and movement is difficult. This con- 
dition is explained by assuming that the inhibitory action of the 
cortico-spinal neurons is cut off and the cell bodies of the spino- 
muscular or lower motor neurons function excessively, and from 
this increased amount of stimulation to the muscles by way of 
the spino-muscular neurons the tone in the muscles is increased 
beyond normal. The cell bodies of the motor fibers of the cord 
are probably stimulated to activity by afferent impulses coming 
in from the periphery and, since there is no inhibition exerted by 
the descending fiber paths, the cells of the lower motor neuron are 
constantly receiving stimulation without any inhibitory influence. 

4. The reflexes are exaggerated. This is because of the 
decreased inhibition from the cortico-spinal neurons, which con- 
dition allows an excessive stimulation of the cells of the lower 
motor neuron, when the afferent system is stimulated by the 
tapping used for testing the reflex. 

5. There is no atrophy except from disuse. This is explained 
by assuming that the lower motor neuron, which is not affected, 
regulates the trophic influences of the tissues supplied. By this 
explanation we are assuming that the function of trophism is 
regulated by way of the spino-muscular neuron from the cell 
bodies in the anterior horn of the cord. 

6. There is no muscular flabbiness. This negative symptom 
is often of much value in differentiating those paralyses which 
may possibly result from lesions involving the fiber paths of the 
cortico-spinal neuron and also some of the cell bodies in the cord 
from which the fibers extend, which constitute the spino-muscular 
neuron. 

7. The circulation to the part involved is usually impaired 
and the skin surfaces of these areas are often bluish and cold. 
It is not easy to explain just how these symptoms result from 
lesions of the upper motor neuron, but it is most likely that they 



336 PHYSIOLOGY : 

are present as a result of the. spasticity and the lack of movement, 
which decreases the circulation of the blood. It is not probable 
that the smooth muscles of the walls of the blood vessels have 
lost their tone, but it may be that these muscles, like the striated 
muscles, are spastic, which would therefore by vaso-constriction 
allow a decreased blood supply to the part. 

8. There is usually a tendency to oedema. This condition 
probably occurs as the result of the decreased venous drainage 
from the affected part, which in turn is due to the decreased muscu- 
lar exercise and the increased resistance offered by the spastic 
musculature through which the veins extend. There is also 
for these same reasons a decreased lymph flow from the parts 
involved. 

9. Sensory disturbances, when they are present, signify 
an involvment of other parts of the cord than the descending 
motor pathways. It usually happens that sensory symptoms 
come on as the disease progresses and are seldom present at the 
outset unless the condition has been due to trauma of the cord. 

Paralyses of this type occur in all forms of cerebral disease, 
such as the hemiplegias, etc. It also occurs in lesions of the cord, 
such as transverse lesions resulting from trauma, hemorrhage, 
tumors, cord inflammations, Pott's disease, and so on. 

Spino- Muscular Paralysis. — The spino-muscular neuron 
is that which extends from the cell bodies located in the anterior 
horn of the gray matter of the spinal cord to the striated muscles. 
This is commonly known as the motor or lower motor neuron. 
Its function, as has been explained above, is that of carrying, 
impulses from the cord to the structure supplied. Paralyses of 
the structures supplied by these neurons may result from patho- 
logical lesions or trauma involving the cell bodies or the nerve 
trunks which carry the axons from these cell bodies to the muscles. 
The symptoms characteristic of lesions of the spino-muscular 
neuron are as follows: 

1. The muscles affected are completely paralyzed from the 
time the paralysis first begins. Revo very is very slow and is 
never complete. This is because the cell bodies of that area of the 



GENERAL AND OSTEOPATHIC. 337 

cord from which the axons arise, which are distributed to the 
muscle, are usually completely destroyed and seldom, if ever, 
regenerate. 

2. All muslces of the paralyzed area are usually not affected, 
but some remain in good condition. This may be explained by 
assuming that the unaffected muscles are supplied by axons from 
cell bodies in the cord, which lie at different levels from the in- 
volved area. 

3. There is no spasticity of the muscles affected by the 
paralysis and the joints of the affected side are relaxed instead 
of being stiff, as in lesions of the upper motor neuron. The move- 
ment of the joints is usually freer than in normal conditions. This 
is due to the decreased nerve supply to these structures, which 
decreases the tone of the muscles involved in the paralysis and 
the muscles about the joint. 

4. The reflexes are dimished or lost according to the extent 
of the lesion. This is explained by the break in the reflex arc 
caused by the degeneration of the motor cells of the cord. 

5. There is always some atrophy of the muscles involved in 
the paralysis, because of the reaction of degeneration following 
the cord lesion, which decreases the trophic influences to the 
structures supplied and which also decreases the nerve supply 
to the vessels, thereby impairing the blood supply to the part. 

6. The muscles of the affected part are always flabby, which 
is explained by the decreased tone of the muscles caused by the 
lack of motor impulses to the muscle fibers. The extent of the 
flabbiness depends upon the extent of the cord involvement. 
There is seldom any improvement from this condition. 

7. The circulation to the part is always poor,, which may 
be due to lack of exercise, decreased venous drainage, or possibly 
it may be due to an involvement of the cell bodies of the antero- 
lateral part of the gray matter of the cord, from which the axons 
arise, which are destined to supply the smooth muscle of the 
arterial walls. The lesion may in this way affect the tone of 
the muscles of the blood vessels. The skin is usually bluish and 
cold, which symptom is more marked than in cases of paralysis 
resulting from cortico-spinal neuron lesions. 



338 physiology: 

8. Oedema is not common in this type of paralysis, as there 
is usually no great resistance offered to the venous drainage, but 
there is usually a clammy perspiration, which may result from 
an involvement of the lower motor neuron fibers, which regu^te 
the secretion of sweat. 

9. Sensory disturbances in this type of paralysis are not 
necessarily present. There is usually no sensory disturbance 
unless the lesion which involves the anterior horn cells of the 
cord also extends to and involves the ascending columns of the 
cord or, if it be a lesion of the nerve root, it may possibly involve 
the ganglia of the posterior root and in this way cause sensory 
disturbance. 

Paralyses due to lesions of the anterior horn cells or their 
nerve trunks and their axones and characterized by symptoms as 
stated above are to be found in the following conditions: 1. 
Infantile spinal paralysis, which is a disease causing degenerative 
changes of the anterior horn cells of the cord; 2. Amyotropic 
lateral sclerosis, which is a disease affecting the lateral columns 
of the cord; 3. Myelitis or general inflammation of the cord, 
and syringomyelia. Symptoms of this type of paralysis are also 
sometimes observed as a result of tumors or hemorrhage occurring 
within the cord and occasionally by neuritis, which involves the 
nerve root or nerve trunk. 

Paralysis Resulting from Lesions of Both Gray and 
White Matter. — In some conditions the pathological lesions 
involving the cord are so extensive that both the gray and white 
matter are affected and the symptoms therefore are of the upper 
and lower motor neuron type; that is, symptoms referable to 
both conditions may be observed. In this case it is often difficult 
to determine from the symptoms the locality and extent of the 
pathological lesion causative of the trouble : 

1. In cases of this type there are usually symptoms of a 
progressive paralysis. All of the muscles of the affected part 
are paralyzed and both sides are usually involved. 

2. Sphincter disturbances are nearly always present, which 
indicate that the pathological lesion has involved the antero- 



GENERAL AND OSTEOPATHIC. 339 

lateral gray matter of the cord, causing degenerative changes 
in the cell bodies supplying the efferent visceral autonomic fibers 
to the sphincters of the rectum and bladder 

3. Trophic disturbances are nearly always present, which, 
as has been explained above, result from the degenerative changes 
occurring in the anterior horn cells of the spinal cord. In addition 
to these symptoms in case of lesion involving gray and white 
matter there will be sjmiptoms of both types, as have been given 
above. 

Paralysis Due to Trauma to the Cord. — In cases of in- 
jury where the cord is affected by bruises, etc., it is usually possi- 
ble to determine by the nature of the symptoms the extent of 
injury which has occurred: 1. There is total paralysis below 
the level of the injury; 2. The muscles supplied by all nerves 
which originate from the cord below the lesion are spastic, as in 
case of cortico-spinal lesions, but in this instance the musculature 
of both sides is affected. The musculature of the two sides may 
not be paralyzed to the same extent; 3. The reflexes are increased 
as in lesions of the upper motor neuron; 4. Sphincter disturb- 
ances are always present, but they may be due to either an in- 
creased or decreased tone of the smooth muscles of the rectum and 
bladder and there may, therefore, be either a continence or in- 
continence of urine and feces as a result. 

Spinal Shock. — Spinal shock may be defined as "A depres- 
sion of the functional power of the nervous tissue distal to the 
lesion, a depression which may extend far from the actual seat 
of injury and manifest itself by various phenomena. " (Stewart.) 
Spinal shock is a condition which occurs in all animals after a 
section, partial section, or other traumatic injury to the cord. 
The symptoms of spinal shock are as follows: 

1. The effect of spinal shock is always greatest in those 
structures supplied by nerve fibers which originate from the cord 
peripheral to the point of injury. Sherrington states that " Spinal 
shock appears to take effect in the aboral direction only." 

2. The reflexes are all lost for a time, which time varies 
directly with the phylogenetic development of the animal. This 



340 physiology: 

is also true for other effects of shock, as the amount of involvement 
and the length of time before recovery from the effects is least 
in the lower forms of life and greatest in monkeys and man. 
"If in a frog the spinal marrow be divided just behind the occiput, 
there are for a very short time no diastaltic actions in the extremi- 
ties. The diastaltic actions speedily return." (Marshall Hall.) 
The " shock" time in the cat is from five to twenty minutes and 
slightly longer in the dog, while in case of monkeys the symptoms 
of the shock last for weeks or months and in the human individual 
the symptoms last even longer than this. For the relations of 
the effects of the osteopathic lesion to spinal shock see Part II, 
of this book. 

Effects of Complete Division of the Cord. — Complete 
division of the cord has often been practiced for the purpose of 
studying the effects in animals, and the same thing has resulted 
from traumatic injury in human individuals. The symptoms of 
complete transection of the cord are as follows: 1. There is 
total paralysis below the level of the section and the muscles are 
completely relaxed. This, however, is not always true in the 
lower animals, as in many cases complete transection of the cord 
produces only the symptoms of spinal shock; 2. The paralysis 
which always occurs in all musculature supplied by nerve fibers, 
which originate from the cord below the region of transection, 
is symmetrical and both sides are involved; 3. The reflexes are 
lost; 4. There is retention of urine; 5. There is vaso-constrictor 
paralysis and priapism; 6. All sensation is lost to pain and 
temperature and usually to touch. These symptoms are always 
present, and if not found to exist it may be immediately decided 
that the cord is not completely sectioned. 

Sensory Disturbances Resulting from Cord Lesions. — 
The physiological perversions of afferent sensations which may 
result from cord and nerve lesions may be classified under two 
general headings, namely, excitatory, or those which produce an 
increased functional activity of the brain, cord, or peripheral 
structures, and inhibitory, or those which produce a decreased 
functional activity of these structures. 



GENERAL AND OSTEOPATHIC. 341 

Under the excitatory disturbances we may include those 
sensations which cause the animal to be more conscious of its ex- 
ternal environment as well as the conditions of its own body. 
These sensations are of many different kinds, such as visual, 
olfactory, auditory, gustatory, pain, temperature, pressure, and 
the internal sensations such as hunger, thirst, etc. There may 
also be an increased activity of those afferent fibers which take 
part in producing reflex effects, which in turn causes increased 
activity of the efferent fibers, and therefore accentuated physio- 
logical activities of the structures supplied by these efferent fibers 
may result. As an example of this, attention may be called to 
the rigidity of muscles supplied from a certain segment which is 
effected reflexly by some visceral disturbance. The converse 
of this condition sometimes results when visceral disturbances 
result from increased sensory stimulation from some peripheral 
or joint surface. We believe this is the explanation of the way 
in which bony lesions are often the cause of visceral disturbances. 
It has been shown that innominate lesions experimentally pro- 
duced are frequently followed by diarrhoea, which may be explained 
by the above statements. 

Under the inhibitory disturbances we may include those 
sensations which cause the animal to be less conscious of its envir- 
onment or its bodily condition. It is believed by some authorities 
that special fibers exist for the transmission of consious sensations, 
but there is little or no positive evidence of the existence of such 
paths. It is most likely that sensations which result in that 
condition we call consciousness are carried by several or possibly 
all of the afferent pathways. It can be readily seen, therefore, 
that anything which interferes with the normal conduction of 
the afferent fibers decreases consciousness. There is also a de- 
creased activity of those bodily functions which are regulated 
reflexly by afferent impulses and such functions as visceromotion, 
vasomotion, secretion, trophism, etc., are affected by lesions 
interfering with the normal conduction of afferent impulses. 

Conditions Causing Excitatory Sensory Disturbances. — 
Various conditions which cause excessive irritability of the dif- 



342 PHYSIOLOGY : 

ferent sensory regions of the cord may cause a condition of hyper- 
sensitiveness of the skin surfaces, causing an augmentation of 
impulses received from the skin. "The irritation in the cord 
may be so great as to lead to hallucinations of sensation; that 
is, to the perception of sensations in the skin which are set up in 
the cord and do not really come from the skin similar in origin 
to the tingling felt in the little finger on compressing the ulnar 
nerve at the elbow." In early stages of certain diseases of the 
cord in which there is irritation following a congestion the patients 
often complain of various sensory disturbances, such as numb- 
ness, tingling, etc. In some cases the perverted sensations con- 
sist of pain, sensations of pressure or burning, and sometimes of 
excessive temperature sensations, either cold or heat. These 
sensations are felt in the referred areas of the skin corresponding 
to the segment of the cord from which their nerve supply is derived. 
The term paresthesia is given to this general condition of perverted 
sensations. 

Conditions Causing Inhibitory Sensory Disturbances. — 
The condition of decreased sensitiveness to afferent impulses is 
known as anaesthesia and may be a result of many causes, as fol- 
lows: 1. Degenerative changes of the cord which extend to 
and involve the ascending columns; 2. Pathological changes 
involving the ganglia of the posterior root; 3. Inflammation, 
such as neuritis, affecting the nerve trunk, and in some cases 
lesions of the skin which prevent the reception or initiation of 
impulses from sensory surfaces. 

The results of such lesions may be quite varied. The various 
sensations may be perverted or lost, such as pain, tactile, tempera- 
ture, and others, and there is also a decreased ability of co-ordina- 
tion known as ataxia. These conditions result because of the 
imperfect transmission of the afferent impulses either from the 
peripheral surface to the cord or from the cord to the brain. 



SECTION VIII 



PHYSIOLOGY OF THE SPECIAL 

SENSES 



CHAPTER XXXVIII. 
CLASSIFICATION OF SENSATIONS. 

The term " sense organ" applies to a mechanism concerned 
in the mediation of some specific sensation and consisting of the 
following structural parts: 1. The peripheral part, or end organ, 
which receives the stimulus; 2. The afferent part, which trans- 
mits the impulse to the central nervous system; and 3. The brain 
centers, which are active in rendering the individual conscious of 
the nature of the stimulating medium causative of these changes. 
A structure consisting of these three parts constitutes what is 
known as an afferent unit. 

Old Classification Inadequate. — The classification found 
in the earlier texts on the physiology of the special senses is in- 
adequate, because physiological research has only recently de- 
termined that a far greater number of the so-called organs of 
special sensation actually exist than had previously been recognized. 
The old classification recognized only five special sensations, 
viz., sight, hearing, smell, taste, and touch. We now know that 
in addition to the first four there are a great many more which 
surely have a right to be considered as sense organs transmitting 
specific sensations, since structurally and functionally they cor- 
respond to the requirements of a sense organ as defined above. 
The so-called special sense of touch has now been found to consist 
of many specific sensations, such as pressure, temperature, pain, 
and probably many others. 

The so-called specific sensations are only a result of the de- 
mands of function, which have, through the ages of phylogenetic 
development, formed some senses more perfectly than others 
for the purposes of protection, etc. The sensations, therefore, 
vary in their degree of specificity from the simplest to the most 

345 



346 PHYSIOLOGY : 

specific, and no definite distinction can be accurately drawn be- 
tween the common and special senses. 

The Sense of Pain. — That the influences of the evolutionary 
factor which have been active in producing this special sense 
may be seen, it seems well to inquire into the function of pain. 
The function of pain is that of protection and not punishment. 
When it is necessary for a part to rest, painful sensations are the 
media by means of which the individual is made to give rest to 
the part affected. An example of this may be noted in the case 
of tubercular joints, the pain being relieved just as soon as the 
part is placed in a firm cast which prevents movement. The 
demand of function in this case is rest, and the painful sensations 
are the media by means of which the individual is forced to rest 
the part. This, then, is a protective reflex, the painful sensations 
reflexly inhibiting the movement of the joints involved. Starling 
interestingly observes that "The reflexes which are excited by 
painful or nocuous stimuli must be regarded as prepotent in that 
their inhibitory effect on other reflexes is more marked than that 
produced by any other quality of stimulus. In the struggle for 
existence the reaction to nocuous stimuli must predominate over 
those due to any other kind, since it is essential for the survival 
of the animal that the stimulus should be removed or avoided, 
so that the animal should escape from its injurious effects." It 
may be seen, therefore, that we cannot separate the special 
senses from the somatic and visceral reflexes. The whole nervous 
system with all of its parts has been developed according to a 
general plan, and that plan has been determined by the demand 
of body functions. 

Internal and External Sensations. — According to one method 
of classification all sensations are divided into two groups, viz., 
external or peripheral sensations and internal or central sensa- 
tions. Under the first group sight, hearing, smell, taste, pressure, 
and temperature sensations are classified, because of the fact that 
their end organs are peripherally located. Under the second 
group those sensations are included which are projected from the 
interior. They constitute the following sensations : Pain, muscle 



GENERAL AND OSTEOPATHIC. 347 

sense, equilibrium, hunger, thirst, sexual sense, fatigue, position, 
itching, tickling, and probably many others. 

Theory of Specific Nerve Energy. — By the doctrine of 
specific nerve energy it is maintained that each afferent unit 
has only one function, that of receiving and transmitting its own 
specific quality or kind of sensation. The optic unit, for example, 
has the power of transmitting only visual sensations, and the 
olfactory unit has the power of transmitting only sensations of 
smell, etc. 

As evidence of the specific theory of nerve conduction the 
following may be given: 1. That artificial stimulation of the 
central end of the optic nerve causes sensation of light has been 
shown experimentally; 2. It had been shown that stimulation of 
the central end of the auditory nerve artificially, produces the 
sensation of sound; 3. It has been shown that stimulation of 
the central end of the corda tympani experimentally, produces 
a sensation of taste. Many other similar examples could be given; 
4. Mechanical pressure when applied to peripheral nerves may 
cause the loss of certain sensations, such as temperature, either 
heat or cold, pain or pressure, etc., without affecting others. Any 
one or more may be retained while others are lost. Such phenome- 
na can be explained by assuming the existence of specific properties 
of the different afferent units; 5. It is also known that similar 
conditions to those just described may occur from traumatic 
or pathological lesions of the spinal cord, which also may be ex- 
plained by assuming that according to this theory only certain 
tracts in the cord are involved, which tracts may be responsible 
for the transmission of the specific impulses which are lacking; 
6. That regeneration of nerve tissue usually restores the lost speci- 
fic function is also evidence of this theory. 

Since there is sufficient evidence to show that such a physio- 
logical specificity does exist, the question of the cause of such 
specificity naturally arises. Obviously this must be explained 
by assuming that one or more of the three parts of the afferent 
unit are responsible or that it is due to the nature of the stimulating 



348 PHYSIOLOGY : 



' 



medium. We will endeavor to arrive at a conclusion by elimina- 
tion: 

1 . That the specificity is not due to any structural peculiarity 
in the nerve fiber, we have the following evidence: (a) no his- 
tological differences in structure have been demonstrated which 
could be responsible for these differences in function; (b) different 
fibers may produce the same effects when allowed to regenerate 
in such a way as to form functional association with the proper 
centers and end organs (see evidence in paragraph following). 
It does not seem probable that specificity of function could be 
due to some specific kind of chemical or physiological change 
occurring in the cell or fibers during conduction, because the 
only physical or chemical changes known to occur during con- 
duction or stimulation are the electrical changes, which seem to 
be the same for all nerves, and an increase in temperature, which 
probably results from the metabolic changes occurring in the 
nerve cell. Metabolic changes are known to occur in nerve cells, 
but no specificity of metabolic change is known to be associated 
with the different nerve cells or fibers. 

2. That some structural peculiarity or adaptation of the 
end organs is responsible for the specificity in many cases we offer 
the following evidence : (a) That if one specific nerve be cut and 
allowed to regenerate to a different end organ, after regeneration 
stimulation of the nerve produces the function of the new end 
organ (for example, the crossing of the cranial and spinal autonomic 
nerves to the salivary glands after regeneration produces opposite 
effects when stimulated; see nerve supply to salivary glands); 
(b) that certain afferent units are capable of reacting to only those 
stimuli which affect their end organs. For example, sensations 
of taste are excited only by fluid substances, and the different 
end organs of taste react only to certain stimuli (see sense of 
taste). The same is true of the sense of smell, as only substances 
in the gaseous form have the power of arousing such sensations. 
In these cases the specificity seems to be due almost wholly to 
the end organs. Further evidence of the function of the end organs 



GENERAL AND OSTEOPATHIC. 349 

as a specific receptor may be observed in the specific receptive 
areas of the skin to heat, cold, pain, etc. 

3. That the greater number of specific sensations are due to 
some structural and functional peculiarity of the brain centers, 
which receive the transmitted sensation, seems to be well estab- 
lished. As evidence of this we have the following: 1. If the con- 
ducting pathway is lacking, stimulation of the end organ produces 
no specific effect; 2. If the center is lacking the stimulation of 
neither the end organ nor the nerve trunk is followed by conscious- 
ness of the specific sensation. 

It may be seen that all three of these parts of the afferent 
unit are absolutely essential to the normal transmission of normal 
specific sensations. Specific sensations may be transmitted arti- 
ficially if the end organ is lacking, but there can be no conscious 
reaction without the cortical centers and their associations being 
intact. 

Measurement of Nerve Force. — Physiology will not have 
a right to be considered as a separate and' independent science 
until we can measure physiological functions and express those 
effects in numbers. This has been done or, we should say, a 
beginning has been made in regard to the physiology of nerve 
tissue. Relative to the measurement of nerve force the following 
facts have been shown: 1. Motor effects resulting from artificial 
stimulation may be increased by increasing the strength of the 
stimulus. The same is true in a general way for all efferent nerves. 
If, for example, a stimulus be applied to the peripheral end of the 
vagus nerve and the secretion of gastric juice carefully observed 
it will be seen that the amount of secretion varies directly with 
the strength of the stimulus applied (up to a certain limit) and the 
time of the application of the stimulus; 2. Secretory effects pro- 
duced by reflex stimulation vary directly in quantity with the 
time and intensity of the stimulus applied. It should be possible 
to measure efferent and reflex effects in ergs of work or dynes of 
force, or both, and in this way determine exactly the relation be- 
tween the nerve energy applied and the amount of work done. 
Conscious effects should also be conditions measurable and com- 



350 physiology: 

parable to the amount of afferent sensation causative of the con- 
scious effects. 

Cutaneous Sensations. — The cutaneous sensations have, 
from the results of recent observations, been divided into two 
general groups, viz., the protopathic sensibilities and the epicritic 
sensibilities. The former group includes those sensations of 
pain and extreme temperature variations. These sensations are 
not well localized and the reaction is not adjusted to the minor 
variations of temperature. End organs for the transmission of 
these sensations are also present in the viscera, in which case it 
would seem that functionally these fibers exist for the purpose of 
protection. It is interesting to note that much specificity exists 
in the pain sensation of the viscera. The handling or cutting 
of an internal viscus may produce no pain, but an irritative sub- 
stance affecting the interior, such as a gall or renal stone, causes 
excessive pain. Thus it may be seen that such sensations answer 
a demand for function — that of protection. 

The second group, the epicritic sensations, include pain and 
temperature, but these sensations are adjusted to the less intense 
stimuli. The temperature reactions, heat and cold, are adjusted 
to the minor variations (from 26° C. to 38° C.) and are sensitive 
to very light pressure stimuli, giving the individual the power of 
tactile discrimination. It is believed that separate fibers exist 
for the mediation of each of these different kinds of sensations. 
End organs of these sensations are located only in skin surfaces. 

In addition to these sensations a group of deep or subcutaneous 
sensations of pressure, pain, and position (muscular sense) exist. 

Distribution of Cutaneous Sensations. — The specific 
end organs or cutaneous receptors of the sensations are located 
irregularly over the skin surface. Each one is specific in that it 
is capable of reacting to only certain kinds of stimuli. There 
are, for example, cold areas, which when touched by a pointed 
instrument transmit only sensations of cold, and the same is true 
for the other sensations, such as warmth, pain, and pressure. 
Sensations normally, therefore, are transmitted by substances 



GENERAL AND OSTEOPATHIC. 351 

affecting these different sensory areas, and thus the individual 
gains a knowledge of the nature of his environment. 

The Deep Sensibilities. — It is now well known that specific 
afferent units exist for the transmission of sensations from the 
deeper structures in the body, such as the muscles and joints. In 
the muscles certain special end organs, the " muscle spindles," 
and in the tendons the organs of Golgi exist for the reception of 
specific sensations, which are transmitted through afferent fibers 
by way of the posterior roots of the cord to the central nervous 
system. Sherrington believes that about one-fourth of the fibers 
in the nerve trunks are afferent in function and that most of such 
fibers are supplied to the afferent receptors in the muscles to the 
muscle spindles. These afferent fibers are functional in that they 
reflexly help to maintain muscle tone, assist in co-ordination of mus- 
cular contraction of single muscles and groups of muscles, and are 
also active in maintaining equilibrium. This explains how in- 
volvement of the posterior horn and the afferent column may cause 
ataxia. Afferent fibers carrying these sensations to the brain 
terminate in the cerebellum and the parietal lobe of the cere- 
brum. The areas receiving these sensations 'posterior central 
convolutions) are probably associated with the motor areas by 
connecting fibers forming a complex cerebral reflex arc. 

The Sense of Thirst. — Sensations of thirst are projected 
from the region of the pharynx, and it would seem that there must 
be some kind of specific afferent fibers extending from this region 
which are involved in the transmission of these sensations. The 
mechanism of the regulation of the quantity of water in the body 
has been discussed elsewhere (see chapter on Excretion), and the 
mechanism of regulating the sense of thirst is not known to have 
any definite connection with the organs of elimination. It seems 
that the specific fibers involved in the sensation of thirst react 
in such a way as to produce conscious sensations of a demand for 
water when the elimination is excessive or when the body water 
content goes below a certain level. It seems, also, that the pharyn- 
geal mucous membrane or possibly certain afferent end organs 
located in this membrane are responsible for the projection of 



352 physiology: 

these sensations, and the- glosso-pharyngeal nerve is probably 
the afferent conducting pathway. As evidence of this it is inter- 
esting to note that dry or salty foods, dust, etc., are known to 
excite a sensation of thirst when allowed to come in contact with 
these membranes. It may also be noted that in the infectious 
diseases, in which the pharyngeal membrane is involved, there 
is often an excessive thirst. 

Sensation of Hunger. — Like the sensation of thirst, hunger 
is also to be classed as one of the internal or common sensations. 
The sense of hunger or appetite is a normal bodily condition occur- 
ring at regular intervals and at certain lengths of time after meals. 
Like the sensation of thirst, sensations of hunger seem to be pro- 
jected to a certain structure, the stomach, but whether a special 
kind of mucous membrane or end organ exists for the projection 
of these sensations is not known. It is thought by some authori- 
ties that this specific sensation is only a modified type of muscle 
sensation projected from the stomach. Because of the fact that 
decerebrated animals show signs of hunger when they are deprived 
of food, it is reasonable to suppose that these sensations are general 
and not referred to any specific cortical area. The sense of hunger 
can usually be relieved by the taking of an excessive quantity of 
water into the stomach, which fact again would indicate that this 
sensation is general rather than specific, and that the sensation is 
caused by some condition of the stomach wall. It is well known 
that muscular exercise, low temperature, etc., cause an increase 
in appetite and it would seem from this that probably some chemi- 
cal changes in the tissues, such as the oxidative changes, might 
constitute in some way a cause for the afferent stimulation of the 
hunger sense, but we have no positive evidence that such is the 
case. 



CHAPTER XXXIX. 
PHYSIOLOGY OF THE EAR. 

The reader is expected to make frequent reference to texts 
on anatomy, as the structure of the organs considered will be only 
very briefly given here. (See Fig. 37.) 

Structure and Function of the External Ear. — The 

outer part, the pinna or lobe of the ear, probably has no function 
in the human, since it is not structurally arranged so that it could 
be of any particular value in the collection or transmission of sound 
waves. The concha is the cone-shaped opening extending from 
the pinna to the meatus, and functions in the conduction of sound 
waves from the exterior into the meatus. The external auditory 
meatus is an irregularly shaped tube about twenty-five millimeters 
in length and extending from the concha to the ear-drum. Its 
chief function is that of conduction of sound waves. The tympanic 
membrane, which separates the external from the middle ear, is 
about one millimeter in thickness and consists of the following 
layers: 1. The external layer is a continuation of the skin, which 
lines the meatus, and its functions are protection and that of 
preventing af ter- vibrations ; 2. The middle layer consists of 
connective tissue and forms the supportive tissue of this membrane ; 
3. The inner layer is a mucous membrane. 

Structure and Function of the Middle Ear. — The ear 
bones are three in number, viz., the malleus, which is in relation 
with the ear drum and weighs about 20 mgs. ; the incus is the sec- 
ond bone of the series and weighs about 25 mgs. ; the stapes is the 
last bone of the series and lies in relation with the fenestra ovalis. 
These bones are held in position by ligaments and small muscles, 
and their function is that of conducting the vibrations set up in 
the ear drum to the fenestra ovalis, where they are in turn trans- 

353 



354 



PHYSIOLOGY i 



mitted by way of the endolymph to the middle ear. In case of 
diseased conditions affecting these bones impairment of the struc- 
tural relations or ankylosis may occur, which impairs hearing. 

The Eustachian tube connects the tympanic cavity with the 
pharynx. Its chief function is that of equalizing the pressure in 
the cavity and upon the ear-drum. The pharyngeal end of this 




Fig. 37.— The Ear. 1, Pinna of the auricle; 2, concha; 3, external auditory meatus; 
4, ear drum; 5, incus; 6, malleus; 7, malleus; 8, tensor tympani; 9, tympanic cavity; 10, 
Eustachian tube; 11, superior semicircular canal; 12, semicircular canal posterior; 13, semi- 
circular canal external; 14, cochlea; 15, internal auditory canal; 16, seventh cranial nerve: 
17, great petrosal nerve; 18, vestibular branch of the eighth nerve; 19, cochlear branch of the 
eighth nerve. (Brubaker, after Sappey.) 



tube is normally closed, thus preventing the passage of foreign 
substances into the middle ear. The valve-like opening of the 
pharyngeal end is regulated by the varying air pressures in the 
pharynx. From the result of inflammatory conditions it is often 
permanently closed, thus limiting the equalization of pressure 
and limiting the power of hearing. 

Transmission of Auditory Sensations. — Auditory sen- 
sations are received upon the tympanic membrane by vibrations 
in the air and are transmitted to the ear bones, the malleus, incus, 
and stapes, in regular order and from here to the fenestra ovalis, 
as explained above. 



GENERAL AND OSTEOPATHIC. 



355 



The Cochlea. — The cochlea consists of a spiral, tube-like 
structure, extending from the membranous opening, the fenestra 
ovalis, and back to a similar structure, the fenestra rotunda. This 
structure consists of two parts, the bony and membranous por- 
tions, which contain a lymph-like fluid, the perilymph. The 
vibrations transmitted by the stapes to the fenestra ovalis are 
carried by way of vibrations in this fluid to the end organs and 
excessive pressure is prevented by the fenestra rotunda acting as 
a safety-valve, thus equalizing the pressure in the endolymph. 
The end organs of the sense of hearing consist of modified epithelial 

cells lying in the cochlea. The 
nerve cells of the cochlear 
branch of the eighth nerve 
lying in the central pillar of 
the cochlea have their den- 
drites extending to the organs 
of Corti, thus forming the 
receptive end organ of hearing. 
These end organs are distrib- 
uted over an area of about 
five square centimeters. The 
organs of Corti are supported 
from the basilar membrane by 
specially modified cells known as Deiters' cells. The axones of 
the nerve cells supplying the organs of Corti extend brainward by 
way of the acoustic division of the eighth cranial nerve. 

The Theory of Hearing. — The most probable of the theories 
advanced for explaining the mechanism of hearing is as follows: 
The vibratory waves produced in the endolymph stimulate the 
hair cells, thus producing the reaction which excites the receptor 
to the transmission of the stimulus. The organs of Corti are 
about 16,500 in number, and it is generally supposed that these 
different cells have the power of reacting to vibrations of different 
pitch, thus differentiating between the different sounds transmitted 
to the ear. It is known, however, that the human individual is 
capable of distinguishing a great many more sounds than this 




Fig. 38. — The Bony Cochlea. 1, Ampulla 
of the superior semicircular canal; 2, ampulla of 
horizontal canal; 3, point of union of superior 
and posterior semicircular canals; 4, ampulla of 
posterior semicircular canal; 5, fenestra ro- 
tunda; 6, fenestra ovale; 7, cochlea. (After 
Brubaker.) 



356 physiology: 

number of receptors could transmit if they are specific for sound 
waves of different pitch, and it has therefore been explained that 
the basal membrane may itself react to the different sound waves. 
The lowest number of vibrations which can be heard by the 
human ear is about thirty per second and the highest is about forty 
thousand per second. 

The Course of Auditory Sensations. — The sound waves 
received by the concha and transmitted to the tympanic 
membrane by way of the external auditory meatus set up vibra- 
tions in the ear-drum, which in turn sets up vibrations in the 
ossicles and these transmit their vibrations to the fenestra ovalis. 
From here the vibration is carried from the labyrinth through 
the scala vestibuli and from here to Deiters' nuclei and the organs 
of Corti in the cochlea. They are here received by the cochlear 
division of the eighth nerve and transmitted to the auditory centers 
in the medulla. They next pass to the corpus trapezoides of the 
opposite side and from here go by way of the tegmentum to the 
inferior quadrigeminal body and the internal geniculate body. 
From the internal geniculate body impulses are carried by fibers 
of the internal capsule by way of the auditory radiations to the 
fissure of Sylvius of the superior temporal lobe. 

Semicircular Canals. — These structures consist of two 
parts, a membranous portion and a bony portion, with perilymph 
between. They are three in number and lie in three planes, each 
at right angles with the other. The ampulla, which is a swelling 
on each end near the utricle, contains the sense organs, the crista 
acustica, which contain hair cells about twenty-five micra in length 
and which are connected with fibers of the vestibular branch of the 
eighth nerve. The functions of these structures, as was first dis- 
covered by Flourens and since demonstrated by other research 
workers, are chiefly the control of co-ordination and muscular loco- 
motion. The functions of these structures were discovered by 
experimentally injuring or destroying one or more of these canals 
in normal animals and observing the symptoms which followed. 
From these studies it has been learned first, that these canals are 
in some way associated with definite movements of the head, eyes, 



GENERAL AND OSTEOPATHIC. 357 

and body; second, body co-ordination; third, the muscles of 
locomotion, and there is some reason to believe that each canal 
is specific in that it has to do with the co-ordinated movements 
of certain groups of muscles. The effects of section or injury to 
the semicircular canals are very similar to that of extirpation of 
the cerebellum. Recovery usually results from injury to the semi- 
circular canals from one month to two years. 

The Utricle and Saccule. — These structures contain sensory 
hair cells, which are probably stimulated by small calcareous 
deposits known as otolyths. It may be that these structures 
are stimulated by sound waves in the perilymph and in this way 
function to some extent in hearing. Another theory is that they 
are concerned with regulating the co-ordination of the position 
of the muscles of the head. There is nothing positively known 
concerning their functions. 



CHAPTER XL. 
THE SENSES OF SMELL AND TASTE. 

End Organs of Smell. — These consist of modified epithelial- 
like cells, which are located in the upper part of the nose and on 
the turbinate bones. Each end organ consists of a small tuft 
of six or eight hair cells. These end organs are distributed over 
an area of about ten square centimeters. Nerve fibers extend 
from them through the cribriform plate of the ethmoid bone and 
terminate in the olfactory bulb. 

Mechanism of the Sense of Smell. — Odors penetrating 
the upper part of the nose during inspiration, or vapors present 
in the posterior nares, affect the end organs. Because odors in 
the posterior nares may affect these end organs, the sense of smell 
is often confused with the sense of taste. Stimulus affecting them 
must be in the form of gas. 

Conduction of Olfactory Sensation. — The stimulus is 
carried from the end organ to the olfactory bulb and from the 
olfactory bulb by way of the olfactory tract to the olfactory lobes 
of the same and opposite side. From the olfactory lobes the 
stimulus goes to the cortex by different pathways, reaching the 
uncinate gyrus of the hippocampal lobe, the nucleus habenularum, 
the gyrus subcallosum, the uncus, and the corpus mammillare. 
It is because of this wide distribution and the complicated asso- 
ciation of the centers of the sense of smell that olfactory memories 
and differentiations are made possible. . 

Properties of Olfactory Sensation. — The primitive func- 
tion of the sense of smell was that of enabling the animal to dis- 
tinguish foods and to aid in protection, etc. In certain lower ani- 
mals the olfactory sensations are much more highly developed than 
in the human, because those animals depend upon this sense 
358 



GENERAL AND OSTEOPATHIC. 359 

to a* much greater extent than do human individuals. A great 
many different kinds of odors are distinguishable, but there are 
no fundamental odors known to exist; i. e., the end organs do not 
have the property of selective activity, as is the case in the sense 
of taste. The olfactory apparatus is subject to fatigue when 
certain odors are smelled continuously for long periods of time. 
As an example of this it is interesting to note that when one re- 
mains in an unventilated room for some time he becomes uncon- 
scious of the foul odor, but if he goes into the open air and then 
returns the foul odor is readily distinguishable. The same con- 
dition occurs if one smells any odoriferous substance for a time. 
It is believed that this phenomenon is due to an actual fatigue of 
the olfactory apparatus, but whether it is the end organs or the 
conducting fibers themselves that become fatigued is not known. 

Sensitiveness of the Sense of Smell. — It is interesting to 
note that the sense of smell is extremely delicate. The dog, for 
example, can follow a "cold trail" of another animal which has 
passed that way many hours, or even days, before. The human 
is able to distinguish certain odors in very dilute solutions. It is 
possible to detect camphor in a dilution of 1 to 400,000, and certain 
musks may be distinguished in much greater dilutions. 

Olfactory sensations are often confused with the sense of 
taste and certain common sensations projected from the nose, 
mouth, and pharynx. This is because the individual is accustomed 
to comparing the odor and taste of many substances used as foods 
and because the volatile liquids, when taken into the mouth, 
pass by the posterior nares and affect the sense of smell at the 
same time that they affect the sense of taste. 

End Organs of the Sense of Taste. — The tongue is the 
most sensitive part, probably because the most specific of the end 
organs are located on this structure. End organs of the sense of 
taste — the taste buds — are located on the tongue, the circum- 
vallate and fungiform papillae. (See Fig. 39.) Other end organs 
of the sense of taste are located on the fauces, the palate, the 
epiglottis, and on the vocal cords. They are distributed over an 
area of about forty square centimeters. 



360 



physiology: 



Fundamental Taste Sensations. — Four specific taste sen- 
sations are known to exist: sweet, which is normally present on 
the tip of the tongue, and bitter on the back part of the tongue. 
Two other fundamental sensations, salty and acid, are known 
to exist, but they have not been definitely located. There may be 
other specific taste sensations, but if such exist their location is 
not known. Others which seem to be possible of recognition may 
be a result of complications of these four or they may be a result 

of the transmission of the sensations of 
taste, sensations of smell, and common 
sensations. 

Nerve Supply. — The anterior two- 
thirds of the tongue receives sensory fibers 
from the lingual nerve and fibers of special 
sensation from the chorda tympani branch 
of the seventh nerve, which goes to the 
tongue by way of the lingual nerve. 
There has been some question as to 
whether fibers of the fifth nerve supply 
the tongue with specific sensations of 
taste. It has been noted after surgical 
operations, in which the ganglion of the 
fifth nerve has been removed, that the 




Fig. 39 
Circumvallate papillae; 
form pappillse. (After Brubaker.) 



ON 27fungi- sense of taste is destroyed, which by some 



is considered evidence that this nerve 
supplies the tongue with special sensory fibers; but insufficient 
evidence has been shown to prove this statement, and it seems 
safe to conclude that the seventh is the only nerve which gives 
fibers carrying specific sensation to the anterior two-thirds of the 
tongue. The posterior one-third of the tongue is supplied by 
the ninth cranial nerve. 

Properties of Taste Sensations. — Many taste sensations 
are confused with the sense of smell, because, as mentioned above, 
these two senses are very closely associated and because many 
substances taken into the mouth are volatile and therefore excite 
the end organs of the sense of smell. Many so-called tastes are 



GENERAL AND OSTEOPATHIC. 361 

really odors and many so-called odors are really tastes. Chloro- 
form, for example, has the power of stimulating the taste of sweet 
and is, therefore, often said to smell sweet. In order that sub- 
stances may excite the end organs of the sense of taste they must 
be in the form of fluids, either liquids or gases. 

It is not positively known how the specificity in taste sensa- 
tions is effected, but it is generally considered that it is due to the 
nature of the end organ receiving the sensation. It may be 
assumed that certain of the end organs of the sense of taste are 
particularly adapted to the reception of only certain kinds of 
stimuli, and in this way the fundamental taste sensations are 
distinguishable. It is possible, however, that there may be some 
particular adaptation of the nerve fibers or the receiving centers, 
which also assists in distinguishing and differentiating taste sensa- 
tions. 



CHAPTER XLI. 



PHYSIOLOGY OF THE EYE. 



The reader is urged to make frequent references to texts on 
anatomy. In fact it is advised that students be given a thorough 
review of the anatomy of each structure before considering the 
physiology. 

Functions of the Sclerotic Coat. — The sclerotic is the 
outer coat of the eyeball and consists of the sclera proper, which 




Fig. 40. — This figure shows a horizontal section of the eyeball. 1, The sclerotic coat; 
2, the cornea; 3, the choroid coat; 4, the iris; 5, the ciliary body; 6, the retina; 7, the crystal- 
line lens; 8, suspensory ligament of the lens; 9, the canal of Schlemm; 10, the canal of Petit; 
11, the optic nerve. (After Deaver.) 

362 







Plate XXV. — I. D., inferior dental to lower teeth. Partial dislocations of the lower 
jaw may irritate the fifth cranial nerve through its branch (I. D.) and produce headaches in 
the temples, facial neuralgia, neuritis, etc; Oph., ophthalmic division of trifacial nerve; C, 
ciliary ganglion to eye; O., otic ganglion on inferior maxillary branch of trifacial nerve; L., 
lingual nerve joined by (ch. ty.) chorda tympani nerve; G. O., great occipital nerve to back of 
scalp; S. P., spheno-palatine ganglion connecting with V, VII, and IX nerves, also sympathetic 
chain (Sym.) ; Vert., vertebral artery joined by its fellow at top of atlas to form the basilar which 
help to supply the brain with blood; III, motor oculi cranial nerve; V, trifacial cranial nerve; 
VI, abducent cranial nerve; VII, facial cranial nerve; IX, glosso-pharyngeal cranial nerve. 



! 



GENERAL AND OSTEOPATHIC. 363 

covers the greater portion of the eyeball. Its function is chiefly 
that of protection. The cornea is the modified anterior portion 
of the sclera and is joined to the sclera by a direct continuity of 
tissue. The cornea is transparent, which property allows the 
free transmission of light. It is supplied with lymph and nerve 
fibers, but has no blood vessels. The functions of the cornea are 
protection and transparency to light, thus allowing the admission 
of light to the aqueous humor. There are five layers of the cornea 
from in front backwards, viz., the anterior epithelial, the elastic 
laminae, the substantia propria, whose function is that of furnish- 
ing lymph for nourishment of the other parts of the eye. The 
fourth, the posterior elastic layer, is commonly known as the mem- 
brane of Descemet. From the periphery of this layer prolonga- 
tions of fibers extend, forming the pectinate ligament. A circular 
opening, the canal of Schlemm, extends around the base of the 
membrane of Descemet. This canal is connected to the lymph 
of the anterior chamber of the eye by a number of openings known 
as the spaces of Fontana, thus forming a mechanisn for the supply 
of lymph to the cornea. (See Fig. 40.) 

Functions of the Choroid Coat. — The choroid is the vas- 
cular coat, whose chief function is to supply nourishment to the 
retina. The iris is the anterior continuation of the choroid coat. 
(See anatomy.) Other functions of the choroid are the regula- 
tion and maintenance of intra-ocular pressure, and the pigment of 
the choroid performs a dioptric function, that of absorption of 
the stray rays of light. 

Functions of the Retina. — The student is referred to texts 
on anatomy and histology for the structure of the retina. The 
anterior termination of the retina on the inner surface of the 
choroid is the ora serrata. The deep pigmentary layer prevents 
the refraction and reflection of light rays. In the posterior part 
of the eye the maculalutea (yellow spot), about two millimeters 
in diameter, contains a highly sensitive portion in its central 
part, the fovea centralis. The blind spot is that portion of the 
retina where the optic nerve enters, and there are therefore no 
end organs specifically sensitive to light in this area. The end 



364 PHYSIOLOGY : 

organs in the retina react to the effects of light and the impulses 
are transmitted by way of the optic nerve. 

The Ciliary Body. — This structure consists of the orbic- 
ularis ciliaris, the ciliary process, and the ciliary muscles. (See 
anatomy and Figs. 40 and 41.) 

The ciliary muscles consist of two groups of fibers. The 
radial fibers originate from the cornea-scleral junction and the 
pectinate ligament. These fibers are inserted into the choroid, 
and their contraction draws the choroid forward and reduces 
the tension on the suspensory ligament of the lens. The function 
of the circular fibers (the muscle of Muller) is not known. 

The Iris. — The iris is an anterior process of the choroid, 
and consists of the following layers: 1. The anterior layer; 2. 
The stroma or supportive tissue containing the vessels of the iris 
and the pigment, which prevents the transmission of light through 
other parts than the central opening of the iris, the pupil; 3. The 
muscles of the iris consist of two layers, the radial fibers the 
contraction of which causes the retraction of the structures of 
the iris and dilation of the pupil, and the circular fibers, contrac- 
tion of which causes just the opposite change — the constriction 
of the pupil. 

Nerve Control of the Iris. — The circular fibers of the iris 
are supplied by the short ciliary branch of the third cervical nerve. 
Stimulation of these fibers causes contraction of the circular 
fibers and constriction of the pupil. The nucleus of the third 
nerve is functionally connected with the anterior quadrigeminal 
body, one of the central terminations of the optic nerve, and it 
is by this mechanism that excessive stimulation of the retina by 
light waves causes reflexly a constriction of the pupil and in this 
way the amount of light admitted to the retina is decreased. 
These nerve connections thus form an automatic adjustable 
mechanism for regulating the amount of light transmitted to 
the retina. 

The radial fibers of the iris receive their nerve supply from 
the cervical autonomics. The pre-ganglionic fibers arise from 
cell bodies lying in the antero-lateral portion of the upper dorsal 




Plate XXVI. — G. T. O., great occipital nerve, supplying the back part of the scalp 
muscles and producing severe headaches when interfered with. Tight muscles in the back of 
the neck, or a twist between the atlas and axis may cause a disturbance of the 2nd cervical 
spinal nerve and result in suboccipital headaches. S. C, spinal cord; O. P. H., ophthalmic 
division of trigeminus. This branch sends nerve twigs up over the eye and therefore frontal 
headaches are often the result of lesions involving this nerve. Ncte the close connection 
existing between this nerve and the sympathetic chain (Sym.), also the spinal nerves (Cer. N.) 
C, ciliary ganglion; Sup.M., superior maxillary division of trigeminus; Inf. M., inferior maxillary 
division of trigeminus; M., Meckel's ganglion; Ch. T., chorda tympani nerve; Ling., lingual 
nerve; Inf. D., inferior dental branch; Sup. L., superior laryngeal branch of the pneumogastric; 
Sym., Sym., sypmathetic nervous chain communicating with the spinal cervical nerves, (Cer. 
N.); B. N., brachial plexus of spinal nerves which go down the arm to fingers; S. G., superior 
cervical ganglion; III, motor oculi cranial nerve; V, trifacial cranial nerve; VI, abducent 
cranial nerve; VII, facial cranial nerve; IX, glosso-pharyngeal cranial nerve; X, X, pneu- 
mogastric cranial nerve; C., C., internal carotid artery; Vt., vertebral artery; Sub., subclavian 
artery. 



GENERAL AND OSTEOPATHIC. 365 

segments of the spinal cord. They pass out to terminate about 
cell bodies in the lateral chain ganglion and pass upward to be 
distributed by way of the long ciliary branch of the ophthalmic 
division of the fifth cervical nerve. Stimulation of these fibers 
or stimulation of. the cervical autonomics causes dilation of the 
pupil. A functional connection exists between the nucleus of 
the third nerve and these cell bodies of the pre-ganglionic fibers 
of this system, thus associating the functions of the dilator and 
constrictor fibers of the iris. 

Stimulation of the sensory spinal or cervical nerves reflexly 
influences the dilator fibers of the pupil by causing a stimulation 
of the cells in the cord from which the pre-ganglionic fibers of 
this system arise. It is interesting to note that the stimulation 
of the spinal autonomic fibers serves as a preparation of the animal 
for emergencies by causing vaso-constriction, increased heart 
action, and pupillary dilation. In this way any extreme external 
stimulation, whether reflexly affecting the central nervous system 
or causing mental excitation, causes reflex stimulation of the 
spinal autonomic system, thus quickly adjusting the animal's 
physical reactions to meet emergencies. By the law of the demand 
of function this physiological adjustment has been developed. 
The fact that one system of fibers supplying the iris arises from 
the upper dorsal is of much osteopathic significance, because it 
is not uncommon to find in clinical practice that bony lesions of 
this region are associated with perverted functions of the eye. 

Conditions Causing Constriction of the Pupil. — 1. 
Stimulation of the optic nerve causes constriction of the pupil by 
reflexly stimulating the third nerve, which supplies the circular 
fibers of the pupil; 2. Stimulation of the third nerve directly; 
3. Section of the fifth (ophthalmic division) causes constriction 
of the pupil, because it cuts off the tone to the radial fibers, thus 
allowing the constrictors full play; 4. Section, paralysis, or over- 
stimulation of the cervical autonomics may cause constriction 
of the pupil in the same way as described above. It is not un- 
common that constricted pupils or pupils which react abnormally 
to light result from lesions of the cervical or upper dorsal regions, 



366 physiology: , 

because of some interference with the functional activities of this 
nerve path; 5. Excess of light on the retina causes constriction 
of the pupil by reflex stimulation of the third nerve; 6. By accomo- 
dation for near objects the pupil is constricted voluntarily; 7. 
Drugs known as myotics such as eserin, cause constriction of 
the pupil; 8. Anesthesia causes constriction of the pupil at first, 
but, if the anesthetic is continued, the opposite reaction results. 

Conditions Causing Dilation of the Pupil. — 1. Section, 
lesion, atrophy, or paralysis of the optic nerve cause dilation of 
the pupils, because by such lesions the reflex tone is cut off from 
the third nerve, which supplies the circular fibers, thus allowing 
the radial fibers to act excessively; 2. Any lesion interfering with 
the normal functions of the third nerve, thus reducing the tone 
of the circular muscles, results in dilation of the pupil; 3. Stimu- 
lation of the fifth cranial nerve or the cervical autonomics causes 
pupillo-dilation by direct stimulation of the radial fibers; 4. 
Stimulation of any sensory spinal or cranial nerve may reflexly 
increase the tone of the cervical autonomics and cause pupillo- 
dilation; 5. Anything which increases the tone of the spinal auto- 
nomics, such as psychic effects, fright, anger, sexual excitement 
etc.; 6. Mydriatics, drugs which cause dilation of the pupil by 
paralyzing the third nerve. Such drugs as cocain, eucain, atropin, 
hyoscyamin, etc. cause these effects; 7. Dyspnea, asphyxia, 
and other forms of abnormal respiration cause dilation of the 
pupil; 8. Anesthetics, when administered excessivley, cause 
dilation of the pupil. 

The Physics of the Eye. — Light waves constitute the nor- 
mal stimulus of the eye. It would be well for the student to review 
the physics of light in some good text on the subject, as space 
would not permit such a review here. Perception of light results 
from a stimulatory effect of light waves on the cellular elements 
of the retina. The transmission of these impulses and their 
effects upon the brain centers results in the production of the 
conscious effects. 

The eye may be compared to the camera in many different 
ways. The opening in the iris, the pupil, corresponds to the 




Plate XXVII. — Normal cervical vertebrae showing spinal nerve connection with nerves 
to teeth and eye. 1 C, 2 C, 3 C, 4 C, 5 C, 6 C, 7 C, cervical vertebrae with the spinal nerves 
emanating from the spinal cord through the foramina, and connecting with the sympathetic 
chain (Sy. M.) in front of the vertebra?. This sympathetic chain connects with the fifth cranial, 
nerve which sends branches to the teeth. C, common carotid; Ext. C, external carotid; 
Int. C, internal carotid: 5, trigeminus nerve; 7, facial nerve; Inf. M., inferior maxillary di- 
vision of the trifacial nerve which supplies the lower teeth; Sup.M., superior maxillary division 
of the same nerve, which supplies the upper teeth. Notice the 5th and 7th nerves connecting 
through the Vidian nerve. (V.) 



GENERAL AND OSTEOPATHIC. 



367 



diaphragm of the camera, and just as the opening in the diaphragm 
of the camera is reduced when accurate definition is wanted, the 
size of the pupil is reduced when one wishes to see certain objects 
more distinctly. By this method a fewer number of rays of light 
are allowed to enter the eye, but these pass through the central 
part of the lens and there is no diffusion. Therefore the formation 
of a more distinct image on the retina results. When the pupil 
is widely dilated waves of light from a great many more different 
angles may enter the eye and one is able to take in his immediate 
surroundings more quickly, but nothing is distinctly seen. In 
this respect the eye is like the universal lens camera. 

Refractive Media of the Eye. — The purposes of the refrac- 
tive media of the eye are transmission of light and the focusing 




theliu-Tn. 

77a.r?'3 M*.rnbra.T>e. 
a. Proper 
■met's fifeynbro.r>e. 
tAe/tum 

cter Muscle of Irit 
/ of Sch/eTnm 
Ci/ia.ry Masc/e 

Ant- pari" of Sc/era. 



Fig. 41. — The right half shows the lens bulging forward in accommodation. The left 
half shows the lens in normal position. (After Brubaker.) 



of the rays in such a way as to avoid diffusion. The refractive 
media of the eye are the cornea, the aqueous humor, the crystalline 
lens, and the vitreous humor. Of these the crystalline lens is 
by far the most important. It is an elastic, highly transparent, 
double convex lens, supported in a capsule which is attached to 
the choroid coat. When the tension on the capsule is reduced 
the anterior portion of the lens bulges forward, thus increasing 
the convexity of the lens, which increases its refractive power. 
If for any reason the lens is imperfect and all rays of light are not 
properly focused upon the retina at any one point imperfect 
vision follows, the condition being known as spherical aberration. 
The outer margin of the lens is less convex than the mid-portion, 



368 



PHYSIOLOGY : 



and when the pupil is widely open rays of light may pass through 
this part, in which they are imperfectly refracted in proportion 
to the other rays. The result is impairment of vision and is 
known as chromatic aberration. The difficulty may be overcome 
by constricting the pupil. The pigment of the retina effects 
the absorption of the stray rays of light and thus prevents diffusion. 
In this way minor disturbances in vision resulting from errors of 
the lens, if not too great, are partly prevented. 




Fig. 42. — Showing the condition occuring in a hypermetropic eye. 
light are seen to focus at a point behind the retina. (After Brubaker.) 



The parallel rays of 



Conditions Causing Imperfect Refraction. — Normal re- 
fraction occuring in the normal eye is known as emmetropia. 
Hypermetropia is a condition of abnormal refraction, in which 
the rays of light come to a focus behind the retina. The condi- 




Fig. 43. — This figure shows the rays 
of light coming to a focus behind the retina 
because the eyeball is too short. (Brubaker.) 




Fig. 44. — This figure shows the correc- 
tion of the condition seen in Fig. 45 by the 
use of a double convex lens. (Brubaker.) 



tion may be due to the eyeball being too short or the lens being 
insufficiently convex. Myopia is a condition of abnormal re- 
fraction, in which the rays of light come to a focus in front of the 




Plate XXVIII. — This plate shows the same nerves and blood vessels as Plate XXVII, 
but a special lesion is shown. The second cervical vertebra, (2 C) or axis, is rotated and irrita- 
ting the spinal nerves, and reflexly, disturbing the terminal nerves to the teeth through the 
trifacial nerve, which might produce neuralgic symptoms. Deadening the same, or killing 
the nerve in the teeth will not lessen the irritation to that nerve, which is constantly produced 
by the lesion existing at the axis. Two upper teeth are shown with the nerves " killed. " 

C, common carotid; Ex. C, external carotid; Int. C, internal carotid; 5, trigeminus 
nerve; 7, facial nerve; Inf. M., inferior maxillary division of the trifacial nerve, which supplies 
the lower teeth; Sup. M., superior maxillary division of the same nerve, which supplies the upper 
teeth. Notice the 5th and 7th nerves connecting through the Vidian nerve (V.) 



GENERAL AND OSTEOPATHIC 



369 





Fig. 45. — This figure shows a condi- 
tion of myopia. The parallel rays of light 
are seen to focus in front of the retina be- 
cause the eye ball is too long. (After Bru- 
baker.) 



Fig. 46. — This hgure shows the same 
condition as in Fig. 43. Corrected by the 
use of a double concave lens. (After Bru- 
baker.) 



retina. This condition is just the opposite of hypermetropia 
and is due to the eyeball being too long or to the lens being too 
convex. Astigmatism is a condition of imperfect refraction 
caused by certain defects in the lens, so that the light rays in 
different meridians are not focused at the same point on the 
retina. This condition may be due to many different causes. 

Mechanism of Accommodation. — It has been shown above 
how, when the radial fibers of the ciliary muscle contract, the 
choroid coat in drawn forward. This reduces the tension on the 
suspensory ligament and allows the lens to bulge forward, thus 
increasing the power of refraction. The lens is sufficiently convex 
in the normal eye to make any special effort of accommodation 




Fig. 47. — The Glands of the Eye. 1, Inner wall of orbit; 2, inner portion of the orbi- 
cularis palpebrarum muscle; 3, attachment of the muscle to the orbit; 4, foramen for nasal 
artery; 5, the tensor tarsi muscle; 6, Meibomian glands; 7, lachrymal glands, orbital portion; 
8, 9, and 10, palpebral portion of lachrymal glands; 11, openings of ducts of lachrymal glands; 
12, and 13 lachrymal puncta. (Brubaker, after Sappey.) 



370 PHYSIOLOGY : 

unnecessary except in exceptional cases, when especially accurate 
perception is nescesary. 

Accessory Structures of the Eye. — The eyelids consist 
of an outer covering of skin and an inner lining of modified epithe- 
lium, the conjunctiva. Between these two layers a semilunar 
cartilage, known as the tarsus cartilage, is contained, which forms 
the framework of the upper lids. 

The lachrymal apparatus consists of a number of glands 
located in the upper, outer part of the orbital cavity. These 
glands are supplied by branches of the fifth nerve and the cervical 
autonomics. Their secretion, the tears, which consist of water 
and inorganic salts, is emptied upon the conjunctiva and eyeball 
for the purpose of lubrication and protection. There are from 
seven to ten ducts, which open into the upper, outer part of the 
conjunctiva. The tears are normally drained away by way of 
the lachrymal puncta into the lachrymal ducts and the nasal 
ducts. 

The Meibomian glands are embedded in the posterior portion 
of the lids. They secrete a lubricant for the lids. The lashes 
are hair projections extending from the outer margins of the lids 
and serve the purpose of protection. 




Plate XXIX.- — This plate shows the complete nerve supply to the muscles of the eye, 
also the nerve connection through the sympathetic with the cervical nerves by way of the 
rami communicantes. 

II, optic nerve; III, motor-oculi; IV, pathetic; V, trifacial; VI, abducent; VII, facial; 
IX, glosso-pharyngeal ; X, pneumogastric; Oph., ophthalmic division of the trifacial; Int. C, 
internal carotid; M., Meckel's ganglion; Ch. Ty., chorda tympani nerve communicating with 
the lingual (L) ; Inf. D., inferior dental; Sup. L., superior laryngeal; S. G., superior cervical 
ganglion; M. G., middle cervical ganglion; I.G., inferior cervical gangilon; B, basilar artery; 
Vert., vertebral artery; C. C., common carotid artery; Sub., subclavian artery; Sym., sym- 
pathetic chain; S. C., spinal cord. 



! 



SECTION IX 



RESULTS OF DR. McCONNELL'S 
I RESEARCH WORK 



PART II. 

OSTEOPATHIC RESEARCH IN PHYSIOLOGY. 



THE OSTEOPATHIC LESION. 

Carl P. McConnell, D. O., Chicago. 



CHAPTER XLII. 
STATEMENT OF PROBLEMS. 

The practical application of the sciences that comprise the 
study of osteopathy is undoubtedly the most difficult problem 
that confronts the student. He is not only brought face to face 
with the correlation and unification of several allied branches of 
study, but the application, the art, of the dependent therapeutics 
is no small matter, for his success or ability is measured by his 
being able to apply his knowledge. And where the really severe 
test comes is at the bedside, for here typical presentations and 
classical descriptions are by far in the minority. Both logically 
and practically familiarity with the anatomical structure is the 
first requisite. Without thorough knowledge of every part of 
the field of possible operation no one for a moment would think 
of entrusting himself to the surgeon who has not all of the facts 
at his " finger ends." The same situation is just as true with 
the osteopath, for upon his knowledge of the facts will the serious 
question of life or death often depend. In fact it is a reductio 
ad absurdum to even think that one can know much about any 

373 



374 physiology: 

mechanism who is not perfectly familiar with the component 
parts and their relationship. Although with the human mechan- 
ism the analogy can be carried too far, for here we are dealing 
with a vital mechanism, nevertheless a most thorough workable 
knowledge is absolutely demanded. 

Following an understanding of the anatomical parts, the 
next requisite is applied physiology. Here in reality is the pivot 
of a triplex. First, a familiarity of the make-up of the organism ; 
second, the practical application of the innumerable functions, 
the physiology, not only separately but in their inter-relationship; 
third, the art, the technique, as is implied in all that adjustment 
means both mechanically and skillfully. But as we have just 
said, the physiological, the functional requisite is the central 
criterion. The functioning of a mechanism is the final test, foi\ 
without this all other experience or proof is useless. 

Variation of the human organism is the one great stumbling 
block of the tyro. This includes a large field. And so, frequently 
text-book information may be a source of confusion for the student 
unless he has early acquired the rare ability of unifying and classi- 
fying his reading knowledge and applying it to his practical ob- 
servations and experience. The most obvious of all the anatom- 
ical does not always follow the text descriptions by considerable; 
variation is frequently rampant here and the law of averages must 
be consulted. There is the varying quality of tissue dependent 
upon heredity, nutrition, pathology, age, etc. Position, modi- 
fication, alteration of tissue and viscus frequently comprise prob- 
lems of no small moment. Then the mental characteristics in- 
volve study of greater or less magnitude. In short, individuality 
of every human organism is a most vital and persistent question 
proposed for everyday solution. So it all comes back to the 
physiologic test, whether the case at issue, no matter what seem- 
ing variations it may present, approaches the norm of functional 
practicality. 

At best we can grasp only a slight understanding of the intri- 
cate functioning of the body. Certain broad principles give us 
a working basis upon which we can build a rational superstructure 



GENERAL AND OSTEOPATHIC. 375 

of therapeutics. First and foremost the body organism is a self- 
reparative mechanism. No system of treatment can cure or 
repair a damaged tissue. Nature alone takes care of this. All 
any one can do is simply to assist her in so far as compatible with 
mechanical obstructions, hygiene, environment, diet, and sur- 
gical cleanliness. This is the limit of finite endeavor. It has 
nothing to do with the actual reparative process — it simply gives 
nature a greater opportunity to assert her powers. Conversely 
great care must be taken not to promulgate meddlesome activity. 

The body organism is in a constant state of flux, of change. 
There is not, and can not be, a perfect organism. An ideal fault- 
lessness means an imaginary standard of excellence. Such a 
state can not be so long as there is growth, development, and re- 
pair. The potentialities of the germ-plasm and the response to 
environment preclude such a thing as an absolute perfection. We 
are part of nature and our response and growth are in accordance 
with biologic laws. The principles remain the same but there is 
an ever varying application of its laws. But this is not to be 
interpreted that the body is not a complete organism. It contains 
all the forces and resources necessary for growth, repair, and re- 
cuperation under the ordinary stress and strain of environment. 
Naturally there is a limit wherein accidental happenings, destruc- 
tive pathologic conditions, extraordinary virulence, and marked 
lowered resistance can not be successfully combated. In other 
words the material, physical body represents a complete organism, 
but necessarily a self -limited mechanism in accordance to physical 
and chemical laws. The life principle is hedged in and restricted 
in its material expressions compatible with the laws of the physical. 
Consequently the osteopathic application is based upon an under- 
standing of these laws, and therapeutic technique is nothing more 
nor less than an appreciation that nature's resources and limitations 
are supreme. This includes the absolute boundaries of finite 
ability. 

With all of our present-day knowledge we know very little 
of the actual happenings that take place in the cell. The cell 
contains all the resources, active and potential, and is, in a sense, 



376 physiology: 

the final arbitrator. It represents the criterion of physical and 
chemical completeness. Its measurements and restrictions is 
the ultima Thule. But this statement, however, should be some- 
what qualified: The cell is the physical foundation of the body 
and in its primitive form contains potentially the fundamental 
properties of an organism, but specialization of structure is at- 
tained at the expense of certain attributes. Certain technical 
methods give us a bare outline of its structural make-up, but as 
to the dependent processes of molecular changes we know next 
to nothing. We are in a somewhat similar situation of a being 
high in the heavens that sees an occasional house of a village 
amongst the trees below. He knows something of the activities 
as a unit but realizes that the many intricacies of the different 
households contain the "vital principle" that in the aggregate 
characterize the special functions and the individuality of the 
organ. He may remain in his position until the leaves of the 
trees have disappeared and his view will be much clearer, but his 
knowledge of vital functions will not be correspondingly increased.* 

Although the cell is the unit of structural mass and functional 
expression and contains limited resources of its own, still it is 
dependent upon the organism as a whole for continued activity. 
It is the interdependence of all cells and organs that expresses 
the individuality of an organism. The controlling nervous sys- 
tem, the circulating vascular system with its properties of nutrition 
and chemical co-ordination correlate and concatenate the organism. 
All of this intricate and complex structure constitutes the complete 
being. 

The student should ever keep before him that the body is a 
plastic organism. The variations and adaptations are not only 
the result of the germ-plasm characteristics, but there is an in- 
ternal mechanism that responds to environmental conditions. 
Environmental forces include a wide range of sources, from habits to 
climatic changes and from dietetic effects to respiratory influence, 
culture, modes of life, chemical changes, etc. All of these have 



* More than seventy years ago Schwann said that the life of the organism is the sum of 
the lives (chemical and physical changes) of the individual cells. 



GENERAL AND OSTEOPATHIC. 377 

either a direct or indirect influence upon the body and thus health 
or ill-health may be the consequence. 

Growth and development of the body are very dependent 
upon exercise. Indeed, without exercise tissue and viscera are 
unable to fully develop. The body is as dependent upon exercise 
as it is upon oxygenation and food. The growing child abso- 
lutely requires that every muscle be brought into activity in order 
that not only the physical mechanism as exemplified in muscles 
and viscera be brought to a state of usefulness, but also in order 
that the brain itself be fully developed. This is a fundamental 
requirement. 

All of the above necessities are more or less directly influenced 
and controlled by the nervous system. The afferent and efferent 
system work together as a physiologic unit. In a sense the affer- 
ent impulse is the source of all energy, for without its functioning 
and the controlling tissue, the nervous system, is unable to func- 
tion. Plasticity of the body largely rests with the adaptability 
of the afferent and efferent system. Herein is the avenue of 
approach to the so-termed vital activities, even to the entrance 
of external influences that pertain to mental growth. Indeed, the 
physical and mental are complemental, and both are based upon 
the same physiologic law. The intricacy and complexity of the 
interrelated whole is brought into harmony through the medium 
of this system. This is the key in a broad sense to the importance 
of the osteopathic lesion as a factor of the health problem. 

The osteopathic lesion, as we shall see, rests for its interpre- 
tation upon a broad biologic basis. It is fundamentally a block- 
age to the afferent impulse. And any interference with the afferent 
integrity means disorder, disease, for thereby growth, develop- 
ment, repair of tissue and vital resistance is impaired. The body 
being built upon mechanical lines is subject to mal-adjustment 
whether of bone, muscle, ligament or viscus, and this at once 
implies interference with the afferent impulse and as a result 
the concatenated whole is deranged. 

The spinal column is of first consideration owing to its rela- 
tionship to the superimposed segments termed the spinal cord. 



378 physiology: 

This is the significance of the vertebral lesion. However, the 
afferent impulse may become disturbed elsewhere, as for examples, 
displacements and adhesions of a viscus, a pelvic derangement 
or a weak foot. The physiologic fundamentals are the same, 
although the application mechanically may be different. The 
therapeutic danger lies in being lost in a maze of details and thereby 
not keeping the broad physiologic application intact. 

Let us outline in this sketch two or three points a little more 
fully, which, in our opinion, contain the essence of the relationship 
of the osteopathic lesion to physiology: 

(a) The body as a unit. We commonly speak of the body 
as being a machine. This is true to a large extent, for the laws 
of mechanics and mathematics are applicable to its structural 
make-up to a surprising degree. But it is much more than a 
machine, for what we regard as physical and chemical laws do 
not comprise all of the constituent laws of physiologic processes. 
There is the biotic energy which, according to our present under- 
standing of physics and chemistry, is separate and distinct (still 
dependent), although we are unable to define it. 

There is no part of the body that is really autocratic. Hering 
has well said that "the human body does not receive the impulse 
of life like a machine from one point, but each single atom of the 
different organs bears its vitalizing power in itself." We must 
view the body as a most complex mechanism, wherein every part 
has a distinct relation to every other part. This inter-relation is 
controlled by the nervous system. And the afferent impulse is 
the source of all physiologic activity. Consequently anything 
that impairs the afferent impulse will more or less profoundly 
disturb the entire mechanism in part or as a whole, or correspond- 
ing to the extent of blockage or degree of irritation. 

(b) The relation of the nervous system to the body unit. 
It should be constantly emphasized that the nervous system is 
the controlling factor. Whether the process is physical or mental y 
a very minor tissue growth or repair, a spinal cord reflex, a stimulus 
to the so-called vital centers of the medulla, or a mental process, 
the incoming afferent impulses initiate the dependent train of 



GENERAL AND OSTEOPATHIC. 379 

activities. And every part of the body contributes to a greater 
or less degree its quota of impulses, thus bringing into definite 
relationship a concatenated whole.* The afferent and efferent 
systems are to a certain extent plastic, which allows conformance 
to demands of growth and repair as well as requisition of co- 
ordinate variations and environmental changes. Thus no center is 
isolated, but instead it is subject to peripheral sensory impulses. 
The center does not originate impulses, but is quite dependent 
upon the incoming stimulus. Exercise, fresh air, diet, environ- 
ment, and all that constitutes hygiene has a profound effect 
necessarily upon the body organism. Thus by virtue of this 
regulating mechanism the body works as a whole, nothing more 
nor less. There is no automatism, but instead the sensory im- 
pulses and the quantity and quality of the blood is the inception 
of physiologic changes. Hence .the significance and the impor- 
tance of the osteopathic lesion can not be gainsaid. Obstruction 
of circulation or of nervous impulses strikes at the very fundamen- 
tals of health or wholeness. 

(c) The osteopathic lesion. This has been defined by Hulett 
as "any structural perversion which by pressure produces or 
maintains functional disturbance." We have emphasized the 
structural make-up, the functional test, the body unit, and the 
regulating mechanism. By virtue of all of this, biologically an 
intact unit is absolutely essential to health. Hence the osteo- 
pathic concept rests upon the solid basis of physiologic principles. 



* "Every vital phenomenon may be regarded as a reaction conditioned by some change in 
the environment of the animal and adapted to its preservation." "The object of a nervous 
system is to ensure the co-operation of the whole organism in any reaction to changes in its 
surroundings. ' ' (Starling — ' ' Human Physiology. ") 



CHAPTER XLIII. 
EXPERIMENTAL WORK.* 

We have been carrying on a series of experiments for the 
past nine years to determine the nature of the osteopathic lesion 
on animals. The work has comprised a stud}^ of more than a 
hundred animals, principally dogs, a few rabbits and guinea 
pigs. We do not wish to be understood that we consider the 
work finished in any sense, but instead simply a start in which 
we believe is an important scientific part of the osteopathic prob- 
lem. Other workers have for a number of years been engaged in 
the scientific field on allied phases. Dr. Deason has in his 
experiments verified certain parts of our findings. 

The production of the lesion is a simple but still a very 
important matter. It cannot be performed successfully in a hap- 
hazard manner. Strict attention to the thorough relaxation of 
tissues about the field of operation and definite application of 
mechanical principles are demanded. After selecting a healthy 
animal (preferably a small or medium-sized dog), surgical anes- 
thesia is best; although in our later experiments we would say it 
it not necessary, for we have been able to accomplish results quite 
easily without resorting to anesthesia. Relaxation of the area 
of intended operation is an essential for ease of lesion production. 
Having determined the character of osteopathic lesion desired — 
that is, right or left rotation, or hyperextension, or hyperflexion, 
or combination of these — the second essential is to apply definite 
mechanical principles. Bringing the fulcrum to bear at just the 
desired point when the tissues are thoroughly relaxed is as neces- 
sary in producing a lesion as in adjusting one. Much strength 



* For literature, see Author's references: A. O. A. Jour., Sept. and Dee., 1905; May and 
Aug., 190G; June, 1911; Sept., 1912; A. T. Still Research Institute Bulletin No. I. The 
publishers have kindly permitted the use of the above articles. 

380 



GENERAL AND OSTEOPATHIC. 381 

can be wasted if the leverage is not right; otherwise compara- 
tively few pounds' exertion will accomplish the result. A simple 
way is to place the animal flat upon the belly, and thoroughly 
relaxed; then, while an assistant bears down with his thumbs 
upon the selected vertebra, the operator grasps the animal by the 
hind legs and exerts traction in line with the spinal column until 
the spinal muscles thoroughly relax and stretch; then immedi- 
ately, while still maintaining the traction, hyperextend and rotate 
the spine until the desired point is felt to give and slip. Or, 
while still maintaining the traction, have the assistant suddenly 
exert pressure, a thrust, upon the desired vertebra. It is simply 
a question of applying the indicated mechanics. Various leverages 
may be utilized. Frequently we place a small block transversely 
under the animal, directly be neath the fulcrum, which assists 
in separating the parts to be lesioned as well as rendering the 
field a little more stable. 

The traumatism is not carried to a point whence tissues are 
torn or lacerated. The object is to obtain a slight slipping or 
mal-adjustment of the articular surfaces. If done correctly — 
that is, specifically — little force is required. The immediate 
noticeable results are malalignment of the vertebrae, malposition 
of the ribs corresponding to the damaged vertebrae if the lesion is 
a dorsal one, and contraction of the spinal muscles of the same 
segments. These changes are readily palpated. After recovery 
from anesthesia the above characteristics are evident, with the 
added ones of tenderness and rigidity. Superficial muscular 
contraction usually subsides, but not always, until only the deep 
spinal muscles adjoining the lesion are palpably contracted. In 
some cases it is noted that upon movement the back is stiff and 
tender. In others such is not the case, and they shortly show no 
apparent ill effects. Later on a number present more or less sys- 
temic disturbances, depending upon the locality of the lesion. 
The periods of observation have ranged from three to eighty days — 
that is, the time from production of the lesion to autopsy. 



382 physiology: 

DISSECTION OF THE LESION.* 

Before the lesion is dissected a thorough autopsy is made 
in each case and specimens secured of various organs and tissues, 
whether they show any pathological changes or not, or correspond 
nervously with the osteopathic lesion. The special reason for the 
microscopic study of so much material will be stated later. 

The dissection of the lesion and the securing and fixing of the 
specimens is executed with much care. After a thorough exam- 
ination of all the viscera and tissues, with the exception of the 
brain, is noted, resection of six to eight vertebrae, including the 
ribs and contiguous muscles, ligaments and nerves intact and 
in situ, is made; that is, the spinal-column segments two to four 
vertebrae above and below the lesion are removed in order to 
facilitate careful and expeditious dissection and examination. 
At this point, and up to the severance of the damaged constraining 
ligaments, malformation and rigidity of the lesion is readily noted. 
Even the contractured muscles and parts of muscles do not relax. 
It is the deep contiguous muscles of the multifidus spina? that are 
most involved. The spinal muscles are carefully separated and 
removed, as well as the nerve fibers supplying the same. Next, 
the sympathetic chains and their connecting fibers and rami 
are removed with as little traumatism as possible. Frequently 
small hemorrhagic points are detected in the sympathetic tissues 
corresponding to the lesion. Following this the ribs are removed 
and the intercostal nerve, artery, and vein retained. In a few 
instances bundles of intercostal muscle fibers are found contrac- 
tured, and also slight hemorrhages of the surrounding intercostal 
tissues are detected. After the spinal muscles, ribs, sympathetics, 
and intercostal structures have been dissected and removed, 
the rigidity of the remaining vertebra? does not seem to be specially 
impaired. The next step, separation and removal one by one of 
the six or eight vertebra?, requires particular pains. Severance 
of the articular ligaments and dissection of the tissues intact 



*I am specially indebted to my associate, Dr. Frank C. Farmer, for valuable aid and sug- 
gestions. He has done most of the dissection, which in itself requires unusual experience and 
skill. 



GENERAL AND OSTEOPATHIC. 383 

passing through the intervertebral foramen require considerable 
skill in order not to produce artefacts. Also, great care has to 
be taken in separating the spinal-cord membrane from its sus- 
pensory ligaments and tissues. 

In the lesion itself, we fail to see where there is any perceptible 
partial occlusion of the spinal foramen by the encroaching bony 
tissues in the great majority of cases. Slight tension of the in- 
cased fibrous tissue anchoring the structures passing through the 
opening may readily occur. This in itself, in one sense, will 
act as an occluding factor. But careful microscopic examination 
does not reveal any greater damage to nerves or vessels here than 
at several other places, and the theory of pressure or inhibitory 
lesions per se at this particular area is untenable. Strain of the 
spinal-column muscles alone, especially an unbalanced tension, 
will unquestionably produce a temporary lesion, but not often 
a permanent one. After a number of days' rest the muscles will, 
to a great extent, return to the normal, unless there is a very active 
disturbing factor, such, for example, as considerable inflammation. 
Even in those cases where there is marked contracture, complete 
removal of the muscles produces very little, and at times no per- 
ceptible, palpable change in the vertebral rigidity. This does 
not apply, however, to ribs, for removal of the intercostal muscles 
allows comparative freedom of the range of rib movement, owing 
to the relatively small articulating surface. Consequently, it 
is found that the permanent vertebral lesion is maintained by 
overstretched and damaged articular ligaments. Sever either 
the capsules of the articular processes or the ligaments of the 
vertebral bodies and considerable motion is immediately obtained. 
The ligaments of the articular processes are the ones most damaged. 
The intervertebral cartilages of the articular surfaces are commonly 
little involved. This last statement, however, applies to slight 
and moderate lesions. Naturally, in more severe injuries anky- 
losis occurs, which happened in two of the animals. These 
observations apply particularly to the dorsal and lumbar sections. 
The cervical region is different structurally; here, for one feature, 



384 PHYSIOLOGY : 

larger and stronger muscles is an important consideration. Un- 
even traction of cervical muscles followed by contracture can 
easily produce and maintain an osseous lesion. Finally, one 
other point in the lesion involvement is frequently noted, hemor- 
rhagic points within the tissue surrounding the dorsal and ventral 
root bundles and within the membranes of the cord (notably 
between the pia and arachnoid). 

THE MICROSCOPIC EXAMINATION. 

First, a word or two relative to the preservation of tissues. 
This is a most important part of the work. Too much care can 
not be given to the dissection. The tissues should be both gently 
and expeditiously handled. The least possible traumatism is 
demanded. Animal experimentation, in our opinion, is far pref- 
erable in the study of the osteopathic lesion to the dissection of 
the human cadaver. In the former we have the unequaled oppor- 
tunity of examining absolutely fresh and unchanged post-mortem 
material. And in the dog the anatomical and physiological varia- 
tions from the human are practically nil so far as important, criti- 
cal, and dependable observations and study are concerned. 

The various well-known fixing fluids are used, such as alco- 
hol, formalin, Muller's, Orth's, Flemming's, etc., selected accord- 
ing to the various tissues retained and the several staining methods 
to be attempted. As a special precaution portions of the same 
specimens are fixed in more than one fluid and stained by more 
than one method. For an additional "control," in order to re- 
duce errors to a minimum, various normal specimens are passed 
through the same fluids and stains. As to the "control" features 
and the several technique methods, more will be said later. 

Naturally, the greatest interest centers in the microscopical 
findings of the nerves and blood vessels. The Marchi, Weigert- 
Pal, Williamson, and Nissl methods show, without question, 
that the nervous structures of the spinal cord, the spinal nerve 



Note: The following photomicrographs are selected from those published in The A. T. 
Still Research Bulletion No. 1. Photographic work done by Mr. F T. Harmon, Chicago. 



GENERAL AND OSTEOPATHIC 



385 



roots and their branches, and the sympathetics corresponding 
to the lesion, are pathologically involved; while nervous tissues 
of normal animals, fixed, stained, and mounted in the same material 
and at the same time, show no change. Various cell groups in 
the gray matter are disturbed; some are more or less swollen, 
others partly atrophied, and a number normal (Williamson and 
Nissl's methods). Corresponding axon degeneration (beginning 
parenchymatous; Marchi, Donaggio and Weigert-Pal methods) 
is readily noted, and extends above and below the lesion. Our 
studies of the cord have embraced only two or three segments 
above and below the lesion. These changes can readily be classed 
as primary degeneration, which means that the nerve cells are 
nutritionally disturbed. They are not, as a rule, very extensive 




Fig. 48. — Normal nerve fibers of the spinal cord (posterior column). Marchi. X 400. 



386 physiology: 

or severe, but can readily be traced from the nerve centers in the 
cord and posterior root ganglia and sympathetics. In many 
instances they do not include the entire bundle of axones, but 
one-third, one-half, or two-thirds; in some an entire cable is 
degenerated. The posterior nerve roots are most affected, fre 
quently all the fibers. The anterior roots are usually less involved, 
commonly bundles of fibers, not the entire section. In cases 
where the lesion is more severe or the back being stiff for more 
than two vertebrae, the neighboring spinal nerves are foun 
more or less degenerated. 

We have not been able to always clearly trace the degenerate 
paths in the cord (one reason being the paths in the dog are no 
so clearly defined as in the human). But the following paths 
are noted: (a) Definite paths of degeneration in the entry zone 
and in the posterior column, the fasciculus gracilis (GolPs tract) 
and the fasciculus cuneatus (Burdach's tract), also scattered fibers 
corresponding to the descending postero-medial and postero-lateral 
tracts; (b) Posterior cerebello-spinal tract (direct cerebellar 
tract); (c) Ascending anterior cerebello-spinal tract (Gowers' 
tract) . 

It should not be understood that these degenerations have 
destroyed the tracts; within all probability they are amenable 
to treatment. In some cases many fibers are affected, in others 
only a few. The question of regeneration within the central 
nervous system at once arises here, owing to the fact that the 
fibers have no nucleated sheath of Schwann. We think it prob- 
able that moderate changes, due to the osteopathic lesions, are 
amenable, whereas a degenerated lesion would not be. At any 
rate, in those cases where comparatively few axones are involved 
the ultimate results may not prove especially serious, owing to 
the large number of axones, provided the original cause is removed, 
thus eliminating further disturbances. 

Degenerative changes have not been found in every case, 
but in the majority of cases. These changes have been con- 
stant as to locality, and correspond, we believe, to the above 
named tracts, although as to the latter it is possible we are mis- 



GENERAL AND OSTEOPATHIC. 



387 



taken; and it should be noted that all of the degenerated paths 
named above are not necessarily found together in the same speci- 
men. Evidently a series of lesions (osteopathic) of apparently 
the same character may cause a variety of pathologic disturbances. 
The lesion may involve nerve fibers singly, in groups, or possibly 
the entire nerve-trunk; or certain groups of nerve centers or 
-certain cells of groups may be involved. Interesting examples 




Fig. 49. — Transverse section of nerve fibers in the posterior column. Beginning parenchy- 
matous degeneration. The medullary sheaths are largely broken down. Marchi. X 350. 



are: The vascular supply of the lateral cell column is independent 
of that to the motor cells of the ventral horn; differences of func- 
tion are shown in the myelination at five different periods of 
the dorsal roots and dorsal columns. 

It is claimed that most of the nervous impulses from the 
joint surfaces, ligaments, tendons, muscles, and skin, pass from 
the end-organs through the spinal ganglion to the posterior column 
and into the fasciculus gracilis or fasciculus cuneatus. 



388 physiology: 

It is readily seen how important it is that the joint surfaces, 
ligaments, muscles, etc., be normal, responsive, and not held 
immovable and inactive through osseous or muscular lesions, or 
weakened through lack of exercise. We are of the opinion that 
it is largely through the ligamentous changes that the lesion is 
maintained. 

In the nervous tissues we have found the greatest involve- 
ment with the primary sensory neurons. It seems to us that 
herein, to an important extent, lies the inception of the osteopathic 
lesion. Probably most of the impulses, muscular and tactile, 
from the viscera pass through the posterior roots of the spinal 
nerves to the posterior cerebello-spinal tract. It will be recalled 
that this tract is considered a sensory path of the second order. 
It originates from Clarke's column (an area at the inner angle 
of the base of the posterior horn). 

The changes here have not been noted so frequently as in 
the posterior column, one probable reason being that osteopathic 
lesions vary as to severity and extent of involvement. Every lesion 
does not necessarily result in a viscus effect; and it may also 
be said every viscus effect is not always demonstrable pathologi- 
cally, depending upon severity of lesion, length of time, character 
of viscus tissue involved, and how disturbed. 

Several possible explanations as to the cause of the disturbance 
of this tract will suggest themselves. Among the most likely 
we would place first, vascular changes in the cord due to reflex 
vasomotor ataxia.* The vasomotors enter by way of the poste- 
rior root. Then, of course, the impulses of the primary sensory 
neuron are disturbed even before the cells of Clarke's column are 
involved. Another concomitant, or possibly independent factor, 
is the pathologic changes of the viscero-motors due to impair- 
ment of cells in the anterior horn. We do not wish to theorize 
here, but rather to state a few possible explanations in order 
to emphasize the pathologic findings. 

Relative to the third tract we have noted in this report, the 
ascending anterior cerebello-spinal tract, various investigators 

* See McConnell, "The Vasomotors," A. O. A. Jour., Mch., 1912. 



GENERAL AND OSTEOPAHITC. 



389 



have stated that probably pain and temperature impulses pass 
this wslj. (The dorsal nucleus — Clarke's column — also carries 
painful and thermic stimuli.) This tract is probably also a sensory 
path of the second order and arises from cells between the anterior 
and posterior horns. To complete the picture of the posterior 
root fibers, it may be well to recall that within the cord they 
divide, one branch passing up within the posterior column, the 




Fig. 50. — Beginning parenchymatous degeneration of medullated axones of the anterior 
spinal nerve near the cord. Marchi. X 350. 

other downward in the comma tract for a segment or two. Col- 
laterals from both are given off to the gray matter of the immediate 
and upper and lower segments. The collaterals form connections 
with the anterior horns (skeletal reflexes), posterior horns, lateral 
horns (visceral reflexes), and Clarke's column. 

The lower motor neuron rises from cells in the medial, lateral 
and intermedio-lateral columns on the same side and from the 
medial column of the opposite side. The voluntary motor fibers 
originate in the anterior column; and the involuntary fibers, 



390 PHYSIOLOGY : 

sympathetic in function, vasomotor, viscero-motor, secretory, 
inhibitory, rise from the intermedio-lateral column. 

In all of our pathologic findings it seems to us the most sig- 
nificant changes are those of the vascular changes to the ganglia — 
posterior ganglion, cells of the grey matter of the cord, and sympa- 
thetic ganglia. Part of the pathology may possibly originate 
from three sources; probably these are factors of varying and 
various degrees: (a) blockage of normal impulses followed by 
retrograde changes; (b) vasomotor ataxia; (c) traumatic (strain 
and stress) effect to vascular and nervous tissues due to the sub- 
luxated segment. However, the most significant basic and per- 
manent change arises from reflex rather than direct causes. 

An important negative feature is that we have found no 
changes in the axones of the higher motor neurones. Our data 
is based upon the dorsal segments. The most pronounced fiber 
changes are found in the primary sensory neuron and the lower 
motor neuron. These degenerations in the well-marked lesions 
are the same as the others heretofore reported. They are found 
in both halves of the cord, and substantiate the conclusion that 
the osteopathic lesion effect is a reflex effect and not essentially 
a pressure upon the tissues at the point of the spinal foramen exit. 

Pathology is the same usually in both halves of the cord, 
showing that the primary sensory neuron involvement of either 
side is practically equal; the lower motor neuron is degenerated 
(but not of a Wallerian character) primarily from vascular changes 
in the cells of the anterior horn (the higher motor neuron is normal), 
and retrograde changes are not an important factor. 

The affirmative evidence of greatest weight might be that 
pressure at the foramen would disturb the primary sensory neuron 
and the vasomotors to the spinal cord, the latter resulting in 
vascular disturbances to cells of the motor neuron. In this case 
it would not be likely that the pathology of both halves would 
be the same. One will readily grant that the spinal foramen of 
the opposite side, toward which the spinous process is rotated, 
tends to encroach upon the same (spinal nerve), and that the 
training of the firm anchorage about the fibers of the other side 



GENERAL AND OSTEOPATHIC. 



391 




Fig. 51. — Beginning parenchymatous degeneration of the medullated fibers of a section 
near the posterior root ganglicn. Some of the fibers are cut transversely, others longitud- 
inally. Marchi. X 350. 



by separation would act as a blockage.* But the explanation of 
all the pathology, even in this instance, would be more upon the 
plane of reflex changes than of direct pressure. 

Every osteopathic physician of experience is well aware that 
an impacted, rigid, or fibrous ankylosed (articular process) lesion 
is of more serious consequence than a marked twist accompanied 
with greater motion. Then physiologically the functional in- 
ception of nervous activity is afferent integrity, with a reflex 
arc and efferent channel as a structural fundamental. 

We do not wish to imply that the pathology of the osteo- 
pathic lesion always signifies a serious condition any more than 
when one is not feeling well his condition is desperate; but we 
thoroughly believe that it is a demonstrable lesion pathologically 
as well as clinically; that it is a frequent and important etiologic 



* Clinically it is commonly noted that the greatest tenderness is on the side toward which 
the spinous process is rotated. 



392 physiology: 

factor; that it demands specific interference ; and that if adjusted 
and left alone, recovery is the rule. 

The degenerated fibers in the sympathetics appear to be 
largely those of the vasomotors (fine medullated groups, Marchi 
method), but this is a difficult point to positively decide. These 
early changes are, as a rule, a simple beginning primary paren- 
chymatous involvement, and no doubt are amenable, in the 
majority of cases, to recovery when the disturbed nutrition is 
rectified. 

The changes found in the blood vessels are a highly interest- 
ing and elucidating study. The coats of arterioles, capillaries, 
veins, and in some instances the arteries, are found deranged from 
the endothelial cells through the muscle fibers and the outer layer 
into the surrounding tissue. And in the walls through and into 
the surrounding tissues are found, in variable quantities, blood 
corpuscles enmeshed. From an escape of blood plasma to leu- 
cocytal invasion, diapedesis and hemorrhagic foci, the pathologic 
picture is evident. The change is not an intensely destructive 
one, or one beyond a stage of repair. The entire transverse wall 
is not, as a rule, involved, only a portion. In a number of the 
smaller arteries there is a well-defined endarteritis. The in- 
volvement is a hyperemic one, in all probability dependent upon 
vessel relaxation and atony, followed by plasma leakage between 
endothelial cells and escape of corpuscles. This distortion in 
localized areas of the vessel's wall structures is undoubtedly patho- 
logic, due to the varying diapedetic activity. It is specially 
interesting to note that considerable diapedesis occurs about and 
through the ganglionic regions of the spinal cord, posterior root 
ganglion, and sympathetics. This vessel disturbance always 
largely corresponds to the osteopathic lesion so far as the 
involved spinal foramen (both sides) and the injured ligaments 
and muscles are concerned. In many of the dissections the nerves, 
vessels, and connective tissue of the spinal foramen are removed 
intact, likewise the sympathetics and the tissues of the back, so 
that thorough and comprehensive pictures of the lesion are thereby 
secured. The rich nerve and vessel supply to and through the 



GENERAL AND OSTEOPATHIC. 393 

fascia is an interesting study in itself. All of the pathologic 
changes do not correspond absolutely to the osteopathic lesion, 
but the changes above and below are much less marked, and un- 
doubtedly are due to either extension of the traumatic lesion or 
to related nerve paths (probably the latter) . In those cases where 
the mechanical injury is not entirely confined to a single articula- 
tion, pathologic involvement elsewhere is noted corresponding 
to location and degree of initial damage. Then, of course, as 
stated, there is the ramification of fibers above and below the 
segment that should be remembered. The disturbances to the 
vessels of the sympathetic seem to be just as well marked, but it 
is to be noted they are less severe in the adjacent segments above 
and below. The extension of this vasomotor affection to nervously 
related viscera — for example, the stomach and kidneys — is fre- 
quently detected; but visceral lesions will be -discussed presently. 
The hyperemia in -the spinal cord is pronounced, especially 
in the gray matter. Throughout the posterior horns and the 
tips and mesial sides of the anterior horns are the areas most 
disturbed, but not by any means exclusively. The circulatory 
changes vary in different cell groups. This ischemia is greatest 
in the corresponding segment and gradually lessens to a segment, 
sometimes two, above and below the lesion. Congestion, with 
more or less diapedesis of the anterior and posterior spinal-cord 
vessels, is readily noted. In the majority of cases the posterior 
vessels apparently suffer the more, the same as the posterior 
nerve fibers. The additional strain to the anchorage and con- 
nective tissues in the spinal foramen may partly account for this; 
it may be due partly to the peculiarities of vessel distribution and 
termination, and to the fact that the spinal veins have no valves. 
Anticipating, for a moment, a portion of the theoretical conclusion, 
for the sake of emphasis, it would appear that the damage, in- 
ceptively and primarily, would be due to the blockage of the affer- 
ent sensory impulses of the joint structure and encompassing 
tissues, followed by reflex segmental disturbance to the efferent 
vasomotor, motor, and other fibers. In this connection it would 
•be interesting to know the relative severity of nerve cell and fiber 



394 



PHYSIOLOGY 



change due to a disordered viscus,* affecting reflexly the viscero- 
sensory and viscero-motor reflexes. Hyperesthesia and muscular 
contraction of the spinal tissues arising from viscus disturbance 
is a frequent observation, and we profit clinically by these symp- 
toms. Severance of the afferent fibers from viscus to cord and 




Fig. 52. — Nerve cells, axis cylinders and vessels of the tip of the posterior horn. This 
specimen shows only slight involvement. Compare with next figure. Williamson. X 120. 

a histological study of its effects would probably instruct us con- 
siderably. 

These changes, as stated, are detected in varying degree in 
nearly all the arterioles, capillaries, and veins. But in the tissues 
above and below the lesion there is marked diminution in both 



*See Weigs, "The Origin of Disease. " 



GENERAL AND OSTEOPATHIC. 395 

degrees and number of vessels involved. Various well-known 
methods are employed, such as Orth's fluid, formalin, alcohol, 
etc., with hematoxylin and eosin or congo red, and the Marchi 
methods with, at times, an additional lithium carmine stain. 
At the same time, invariably, normal tissues are run through the 
same fluids as a check. These lesions are acute pathologic dis- 
turbances, and not chronic ante-mortem disorders due to other 
causes, or post-mortem changes or artefacts. 

The microscopic muscular changes are clear and well de- 
fined. The contracture is due to an interstitial myositis, wherein 
is easily seen increase of connective tissue and atrophy of the 
muscle fibers. It should be remembered that more or less initial 
muscular contraction subsides after two or three days, and that 
contractures do not, as a rule, embrace all of the muscle fibers, 
but certain groups. The deepest layers, those when contractured 
giving the sensation oi a whipcord on palpation, are mostly in- 
volved. Sometimes only one side is affected. The nerve to these 
fibers is found degenerated, as well as the related arterioles and 
veins. The nerve degeneration is due to the nutritionally disor- 
dered cells of the anterior horn. We do not believe the muscle 
disorder is due to direct traumatism, for certain it is that many 
of them are not factors in maintaining the lesion. This statement 
should not be misinterpreted clinically, for unquestionably muscu- 
lar contractions and general muscular tone is a factor to be reckoned 
with in both producing and adjusting a lesion. 

It is the ligaments that maintain a lesion of the chronic type. 
The injury here is considerable; not necessarily in the sense of 
lacerations and general exudative sequela?. But the ligaments 
are strained and stretched, and more or less hyperplasia follows. 
Proliferative changes and thickening are observed. Arthritis 
involving the cartilages of the articular processes is not the rule. 
In most instances the cartilages of the articular processes are 
normal, as well as the intervertebral disc. But the ligaments 
inclosing the former suffer more than those of the latter. The 
osseous tissue is histologically normal. 

Here a word of caution may be justified. In this study of 



396 PHYSIOLOGY : 

the lesion an attempt has been made to determine just what the 
lesion is — that is, the initial pathologic changes, not its many 
possibilities and variations. There must be definite general 
underlying principles. Our aim has been to seek these, rather 
than to cover the field of pathology, with its many varying phases. 

THE VISCUS EFFECT. 

The effect of osteopathic lesions upon viscera is more readily 
studied, owing to the easier technique of dissection and staining. 
In addition to the histologic methods, at least two important 
organs, the stomach and kidneys, can be clinically studied by 
means of chemical and microscopical analysis. In this sketch 
it does not seem necessary to go into innumerable details. We 
are of the opinion that an outline statement of the facts, with a 
presentation of a few photomicrographs, will prove of consider- 
able interest to the osteopath. 

The lesion effects upon viscera correspond definitely to the 
path of spinal innervation. It would seem that, fundamentally, 
impairment of the vasomotors plays the important role, although 
undoubtedly disturbance of viscero-motor, secretory and other 
nerves are necessary factors, and herein, probably vessel relaxa- 
tion would take place as a reparative process. Congestion and 
inflammation are basic to the large majority of diseases, and in 
all of our experiments we find vessel disturbance a constant feature, 
whether in the immediate locality of the osteopathic lesion or as 
a remote effect, but still related physiologically by way of the 
nerve centers. Consequently, we conclude some involvement 
of the vasomotor mechanism is fundamental to at least a large 
portion of visceral lesions. Remember we are considering only the 
osteopathic experimental field as it is presented to us, and not 
attempting to correlate it with other undoubted etiologic factors. 
The effect upon stomach and intestines is marked. First, clinical 
analysis shows that secretory, motor and digestive powers are 
altered and lessened; that is, of course, if the osteopathic lesion is 
a fairly deep-seated one, affecting the stomach innervation. 



GENERAL AND OSTEOPATHIC. 



397 



Then the histologic examination reveals one or more characteristic 
pathologic changes. In the lesser changes, as in all, we note 
vessel congestion in the submucous coat. Usually accompanying 
this is diapedesis. In the more marked cases the cells of the 
mucous coat are nutritionally involved; there are areas of feeble 
staining and parenchymatous changes, with accompanying path- 
ologic disorder. This is found in areas of both the stomach 
and intestines. These changes, like all the visceral ones found, 
are definite acute ante-mortem lesions. At most, the period of 
time from death of the animal to the tissue being placed in the 
fixing fluid is only a few minutes. 




Fig. 53. — Area near the tip of the posterior horn. Same animal as figure above, but 
different cell group. Note the beginning degeneration of the nerve cells, the pericellular spaces, 
the swollen axis cylinders, the several hyperemic vessels, and the cell infiltration. Other 
groups were found still more disturbed, some less so, while a few are normal. It does not seem 
there can be any question but such lesions are important sites for further pathologic involve- 
ment. Williamson. X 120. 



398 physiology: 

The kidney changes are very interesting. These have taken 
place when the lesion was produced in the section comprising the 
eleventh, twelfth, and thirteenth dorsals only. It would seem 
without question that the vasomotors are principally at fault — 
that is, the initial nervous lesion affecting the kidney is by way of 
these fibers. The disturbance is a vascular one, resulting in con- 
gestion and a typical hemorrhage infiltration. The nephritis, of 
course, is acute, and the urinary findings are characteristic of 
such. The urinary changes are commonly manifested the third 
day, sometimes the fourth and fifth. In two cases correction of 
the lesion was attempted, and in ten and fifteen days respectively 
the urine was negative and remained so. An interesting point 
to note is that the vascular disorder seems to occur first in the 
glomerulus, and between the glomerulus and capsule ; then through- 
out the tubules. There is probably an anatomical reason for 
this, due to the vessel's distribution and ending in the tuft. 

In our experiments the most frequent lesions have occurred 
in stomach, intestines, and kidneys, for we have experimented 
principally with lesions to these organs. And visceral changes 
occur only when the vertebral perversion corresponds to the re- 
spective viscus innervation. The nervous distribution in the dog 
is nearly the same as the human. Those organs having the 
greatest and most sensitive nerve supply are naturally the quick- 
est and easiest affected. 

The liver and spleen in a number of instances were found 
congested. The liver, especially in areas in the middle lobe, 
was involved, and the cellular tissue nutritionally affected. This 
was shown by feeble staining and perivascular infiltration. 

In two cases the pancreas was found acutely disordered. There 
was considerable congestion throughout several of the islands of 
Langerhans (and further study and experiments may reveal that 
this precedes the atrophic changes noted by Opie). The urin- 
alysis after the fourth day showed a moderate amount of sugar. 

The adrenals in one case of lesion of the lower dorsal showed 
a small amount of congestion. 



GENERAL AND OSTEOPATHIC. 399 

A parenchymatous goitre was definitely produced in two 
of the animals. One of these had a lesion between the second and 
third cervicals; the other case between first and second dorsals. 
In both of them several of the near-by lymphatics were enlarged. 
Occasionally the lymphatics, especially near the liver and intestines, 
when these organs were disturbed, showed enlargement. 

All of the visceral lesions were of an acute character and 
correspond definitely with the vertebral or rib lesions. The 
reader is referred to the cuts for more detailed information. 

In later experiments (partly reported in A. 0. A. Journal, 
June, 1911, and others not completed) the spleen, pancreas, and 
adrenals were involved. Goitres have been produced and cured 
in the same animal; this between second and third cervicals 
(probably vasomotors). 

THE CONTROL. 

We are aware that in most experimental work an important 
part is the so-called control. The work parallels surgical experi- 
mentation in so far as many of the principles are concerned. Care 
has been taken in the selection of suitable material. Normal 
animals have been dissected and the tissues microscopically ex- 
amined. Almost invariably specimens of the several viscera not 
physiologically connected with the lesion have been preserved; 
normal nervous and vascular tissues above and below the lesion, 
even from distant parts, as a leg, have been retained; and all 
were fixed, stained, and mounted in the same manner and at the 
same time as the pathologic specimens. This in itself, to us, 
has been a very important control. The tissues . were marked 
and detail notes made. The dissection was unusually careful, 
and with such accessible tissues as the viscera, sympathetics, 
and spinal intercostal fibers, there is no occasion for any damage 
being done. From the living tissue to the fixing fluid, no other 
method offers such a minimum of time for post-mortem changes. 
The pathologic changes are unquestionably ante-mortem, not 
post-mortem or artefacts. They are acute changes, not chronic 



400 PHYSIOLOGY :. 

ones. The changes correspond to the osteopathic lesion, and this- 
was shown by a variety of technique methods. Finally, clinical 
data bears us out. Probably a section of certain nerve fiber s 
(other than has already been done) contiguous to the spinal struc- 
tures would reveal some interesting data, but this requires a high 




Fig. 54. — A normal cell from the posterior horn of the spinal cord. Note the NissI 
granules. NissI, Gothard, Luithlen and Sorgo's modification. X 600. 

degree of surgical skill, and, moreover, a thoroughly trained 
physiologist can do it better, and we have access to their contri- 
butions.* 

CONCLUSION. 

In conclusion, therefore, the following points are submitted 
bearing upon the theoretical and practical interpretation of the 
osteopathic lesion. It seems logical, in view of the above facts,, 
that the explanation of the osteopathic vertebral and rib lesion 
rests upon something more than mere pressure of maladjusted 



* In our later experiments we have added the control features adopted by Dr. Deason. 



GENERAL AND OSTEOPATHIC. 401 

tissue upon nerve fiber or vascular channel; this at best can be 
only a part of the pathological process. In the first place there 
is a physiological disturbance of the muscular, fascial, ligamentous, 
and osseous tissues, which causes interference with the normal 
afferent influences to the spinal-cord centers, and this is more or 
less permanently maintained by the lack of freedom of the normal 
joint movements. This obstruction of normal afferent stimuli 
is only the initial step, for disturbance of innervation through the 
mechanically changed relationship of the structures, physiology 
teaches us, initiates a corresponding and dependent change in 
the spinal-cord segment. The immediate contraction of the 
muscles, for example, and their maintenance show this to be the 
case. Such interference of the ever constant nerve force must 
necessarily disturb functioning, and, as a consequence, the sub- 
sidiary vasomotor centers, with others, are affected. Mere 
inhibition of part of the nerve current, causing resultant disorder 
or certain reflex arcs, would probably affect nutrition. But we 
find vessel relaxation and congestion a prominent feature. The 
arterioles, capillaries, and veins are pathologically affected by 
the disturbed innervation. The blood stream is slowed, the 
endothelial tissue compromised, and plasma exudation takes 
place. This is followed by diapedesis even to the frequent extent 
of hemorrhagic foci, especially in and about the nerve centers of 
the cord and ganglia; and thus nutrition of the local parts is 
jeopardized. This, then, means that the nutritional centers, 
the ganglia, will not receive their full quota of nourishment, and 
thus the integrity of the neuron is impaired and primary paren- 
chymatous degeneration follows. This, we believe, is the explana- 
tion, of at least an important part, of the pathologic inception of 
the osteopathic lesion. Other factors may eventually prove to 
be important contributing features, but our special purpose here 
has been, if possible, to offer an initial working basis. 

Neither macroscopic nor microscopic findings of the tissues 
passing through the spinal foramen warrant the assumption that 
the osteopathic lesion is the result of mechanical pressure per se 
in this region. No doubt strains and tension of the fibrous and 



402 physiology: 

connective tissues here, as elsewhere (and possibly even more so 
owing to the firm anchorage of the tissues), would have their 
effect upon nerve impulses and vascular channels, but the 
histological findings are no more pronounced here than in other 
structures. There is nothing in the examination to lead the 
writer to conclude that the foramen is distinctly lessened in diame- 




Fig. 55. — Degenerated cells from the anterior horn of the spinal cord. The upper cell 
shows chromatolysis ; the cytoplasm is swollen and the nucleus has moved toward the peri- 
phery. The lower is in a stage of atrophy. In the upper right and left periphery of the cut 
are seen two hemorrhagic areas due to venous hyperemia. Nissl, Gothard, Luithlen and 
Sorgo's modification. X 600. 

ter so that it encroaches upon the conducting organs, or that there 
is distinct pressure upon artery, vein, or nerve. The morbid 
histology is the same here as in the corresponding parts. Natur- 
ally, it would take but little strain to disturb nerve currents, but 
it is in the ganglia that the greatest vascular change occurs, not 
along the conducting fibers. Although vasomotor tone, locally, 
even to the point of diapedesis, may occur from mechanical means 
or trauma remote from a center, still it seems to us the phenomena 



GENERAL AND OSTEOPATHIC. 403 

of the osteopathic lesion, clinically and pathologically, point 
distinctly to a central or focal irritation (cord) ; and, moreover, 
the changes in the spinal nerve, artery, and vein would be localized 
in character resultant changes would be different, and less systemic 
and less evenly distributed pathologic involvement if the lesion 
was primarily a blockage at some point within the spinal foramen. 
And, moreover, the degeneration is not Wallerian after the manner 
of a distal end separated from its center. Two or three anatomical 
features stand out prominently in the dissection of the spinal- 
column tissues, viz. : the close contact of the spinal nerve, artery, 
and vein to the superior border of the rib and their firm an- 
chorage within the foramen, clearly exhibiting how easily the 
maladjusted vertebra or rib may disturb these tissues; the fairly 
loose anchorage of the sympathetics, by the parietal layer of the 
pleura, along and near the head of *the ribs, also suggesting that 
rib lesions may disturb sympathetic integrity. However, at 
best, from our observations, pathologic changes here can be only 
a part of the entire morbid picture. 

In the large majority of cases only a portion of the cells are 
affected, likewise the axones. Segments of the cord, as is well 
known, are neither histologically nor physiologically isolated, so 
to speak; neither is the osteopathic lesion a complete severance, 
organically or functionally, of a certain segment. Certain paths 
are more disturbed than others; and from all indications the 
entire neuron suffers, thus pointing, nutritionally, to a central 
effect, with a corresponding disturbance to the subsidiary and 
collateral neurones. This accounts for the pathologic changes 
in near-by segments and ganglia, and, indeed, for the effect upon 
related viscera. No doubt the majority of these early changes 
are amenable to treatment, for the degeneration has not often 
gone beyond a stage of repair. Many lesions, if not all, unques- 
tionably lower the amount of vitality a related tissue or organ 
should receive, and thus are important predisposing etiologic 
factors. 

Nervous tissue, particularly the ganglia from the cord to 
the sympathetics, and the connective tissue are richly supplied 



404 



PHYSIOLOGY : 



with blood (which always indicates intense physiologic activity) . 
This point can not be too greatly emphasized. Osteopathically, 
the greatest disturbance seems to be in these nerve centers. Owing 
to the sensitiveness of nerve cells to circulatory changes, it is a 
slight step from functional impairment to organic disorder. When 
such occurs it is only another short step to visceral impairment. 
The same lesion, apparently, may affect the tissues differently — 
that is, as to precise locality — although all lesions affect the tissue 
more or less the same pathologically. Physiologically and clin- 
ically we know, owing to the neuron morphology, that certain 
paths are related anatomically and physiologically to different 
segments; likewise tissues and viscera to different segments. 





Fig. 56. — Diapedesis in posterior horn midway of base and tip. The two dark spots are 
engorged and dilated veins. The mass of blood corpuscles to the left is from the larger vessel. 
This is only one hemorrhagic spot of several in this specimen, some larger and others smaller, 
scattered throughout the gray matter. X 325. 



GENERAL AND OSTEOPATHIC. 405 

Practically, a thoroughly related structure and a definite tech- 
nique are conducive to either production or correction of the 
osteopathic lesion. 

There can be no question experimentally, as is well known 
clinically, that the osteopathic lesion is an important etiologic 
factor in visceral perversions. We have touched upon the probable 
pathologic explanation, the importance of vasomotor disorder, 
in explaining the pathogenesis of visceral lesions wherein the 
osteopathic lesion is the etiologic factor. It would seem that 
Dr. Louisa Burns' excellent experimental work would have an 
important bearing upon this point. However, this phase of the 
work, the same as the remaining portion, is presented for what it 
may be worth. This is merely a start; but we feel justified in 
saying that we firmly believe the experimental side of osteopathy, 
like the clinical, merits the earnest 'attention of the entire pro- 
fession. We are content for the moment, as has been stated, 
to let the facts speak for themselves; theoretical interpretation 
to a finer degree rightly comes later, when we have much more 
data.* There is an additional practical point we believe should 
be specially emphasized, namely, the importance of leaving the 
osteopathic lesion alone when once something had been accom- 
plished. Dr. Still has continually spoken of this, and experimental 
work substantiates it. Too many of us treat too often and too 
hard, and thus do not allow nature a fair opportunity to repair 
the weakened tissues. 



* We firmly believe the osteopathic lesion has a very potent bearing etiologically upon 
cellular changes. "Variations in minute detail of colloidal arrangement in itself, and in rela- 
tionship to dissolved pabulum in the shape of organic and inorganic crystalloids, lie at the root 
of the varying activities of the cells, and of all physiological and pathological changes." 
(Benjamin Moore, "The Origin and Nature of Life.") 



CHAPTER XLIV. 
THEORETICAL. 

We are prone to overlook the unity of the body. We dis- 
articulate the mechanism at the expense of emphasizing its unity 
of structure. No doubt nerve roots present distinct functions, 
but we should not err by thinking these functions are entirely 
independent. All cells of the body are brought into relation 
and conjunction through the nervous system. Comparative 
anatomy and embryology teach us it is the nervous system that 
unifies the parts. There has been a gradual separation or inte- 
gration of the body unit with a corresponding co-ordination of 
its functions. 

The innumerable afferent impulses, the continuous flow 
of sensory nervous force (not necessarily implying conscious- 
ness), the relation of receptor to effector, the so-termed nervous 
tension due to our external and internal environment is a funda- 
mental essential to well being. This slight and imperceptible 
current of impulses, constantly present, maintains the tone. 

Sensation induces motion and motion induces sensation,* 
both controlled by separate parts of the same nervous mechanism, 
but mutually dependent. And in health there is a constant 
sensory tone as well as muscle tone. Variation of environment 
necessarily produces a change of tonic stimulation. In just so 
far as the body mechanism responds and reacts to tonic stimula- 
tion through its integrals and their co-ordinating functions will 
the effects be stimulating or depressing. Important factors are 
the environmental changes, the intactness of the nervous mech- 
anism, and the integrity of the nutritive supply. We will not 
go into details relative to the first. Nevertheless it covers a wide 

*Morat's "Physiology of the Nervous System." 

406 



GENERAL AND OSTEOPATHIC. 



407 



field from temperature changes, physical and chemical surround- 
ings, sanitary conditions, dietetic habits, to mental attitudes and 
situations. Herein we are especially interested in the blockage 
of the afferent impulses following a certain condition that may 
arise, viz., structural perversion — the so-called osteopathic lesion. 

It is evident from the teachings of physiology that any 
"structural perversion which by pressure produces or maintains 




Fig. 57. — Passive congestion of stomach as shown by the extreme dilation of the vein, 
the ecchymosis, and the actual hemorrhage outside of the vein. This depicts lack of tonicity 
and early degeneration of the vessels. Hematoxylin and eosin. X 75. 



408 PHYSIOLOGY : 

functional disturbance"* must among its initiatory changes 
result in a cessation (partial at least) of the corresponding tension 
or tone. Consequently any physical lesion that lessens mobiluy, 
flexibility, elasticity of tissue, would be an osteopathic lesion. 
And in proportion to the extent of structural rigidity, its locality 
and its length of maintenance will dependent conditions be main- 
fested.f 

Physiology also teaches that the integrity of the neuron is 
dependent upon at least two important conditions; first, its 
nutritive supply; and, second, nervous impulses. Lessen either 
the nutrition or the ever constant nervous tension, and a cor- 
responding body change will be instituted. Immobilization of 
a spinal area, of muscular unbalance is just as much a lesion, al- 
though not necessarily a serious one, as a severe rotation between 
two vertebrae. This condition is an external environmental 
one and disturbs the nervous mechanism after the same manner 
(fundamentally) as an appendiceal lesion or an obstructed com- 
mon bile duct. In each instance the effect is primarily an afferent 
one by way of the posterior spinal ganglion to the associated neu- 
rones of the reflex arc. The inception exemplifies an exaggerated 
physiologic state which, if the lesion is maintained, soon passes 
into a so-called pathologic condition. 

It would not be physiologic to assume that the disturbance 
in its effect rested here. Neither is it necessary to step outside 
of physiologic teachings to assume that the above initiatory change 
is due to a partial closing of a spinal foramen with consequent 
pressure on an emerging axon,t or to assume some fanciful idea 
that the lesion is due to " pressure " on some " osteopathic center. " 
If either of these conditions were present treatment of the condi- 
tion would pass into the realm of operative surgery. Much of 
the misinterpretation arises here from our misunderstanding of 
fundamental anatomy and physiology (although even of this we 



* Hulett's "Principles of Osteopathy." 

t"The nutrition of the nerve cell depends to some extent on its systematic activity. 
Disuse may lead to degeneration, and degeneration or interference with the functional activity 
offone system produces an effect on the functional activity. of another. " 

^Research Institute Bulletin, No. 1. 



GENERAL AND OSTEOPATHIC. 409 

know precious little). We forget, for example, the ramifications 
of the primary sensory neuron and its extensive connections. 
It does not stop at the corresponding segment. Not only do many 
of the fibers extend upward into segments above in addition to 
the association neurones, but others extend downward into lower 
segments.* Consequently, although we have so-called functional 
centers they are not entirely independent. We must ever keep 
in mind the concatenation not only of organ to organ through 
the several ferments, but that nervously there is a constant inter- 
dependence which not only controls and regulates the separate 
tissues and organs, but the mutual interrelation — the unity of 
the body — as well. 

This view of the osteopathic lesion refers to the initiatory 
change only — the interference with afferent impulses. Something 
besides the immediately noticeable dependent motor change 
must take place, for the afferent impulses are essential to the 
nervous balance, equilibrium, of all the tissues, vasomotor and 
secretory and viscero-motor, etc. Naturally, we think of the 
vasomotors first because they control that other master tissue, 
the circulatory system. And without proper nutrition more than 
without sufficient impulses will the neuron become impaired. 
Again physiology teaches us that if the vasomotor tone is impaired 
the vessel dilates, the blood stream is slowed, and the physio- 
logic balance between the fluids of capillary and lymph space is 
disturbed. f 

Although osteopathically the osteopathic lesion in its initia- 
tory phase principally disturbs the well being of external environ- 
ment, we should not overlook the physiologic importance of 
the internal environment as expressed through the nervous system. 
Either a vertebral lesion or an intestinal lesion will be manifested 



*"The articular surfaces of the bones are very richly supplied with sensory nerves. The 
-axons of the sensory nerve cells, entering the spinal cord by its posterior roots, break into 
branches, a short one which descends to the first or second, rarely the third, segment below 
the point of entrance, and a long branch which ascends by way of the posterior tracts to the 
medulla." "Collaterals from axons of sensory roots enter into relationship with the nerve 
cells of the anterior horn. These collaterals, together with some axones from cells of posterior 
horns, carry impulses concerned in those reflexes which affect spinal and other skeletal muscles. 
Thus there is a path from articular surfaces to the spinal muscles that is involved by the bony 
lesion. " — (Louisa Burns, "The Bony Lesion a Cause of Disease. " Jour, of Osteo., Nov., 1909.) 

fResearch Institute Bulletin No. 1. 



410 



PHYSIOLOGY : 



by reflex muscular contraction. In either instance a disturbance 
of afferent fibers initiates the effect upon the nervous tension or 
tone. Unquestionably this teaches us that internal afferent 
tone, for example, the alimentary tract, is essential to health,, 
the same different in degree as external afferent tone. 




Fig. 58. — An early parenchymatous degeneration of the mucous coat of the stomach as- 
shown by the feeble stain taken up and in plaees by its complete absence. In a few places 
there is partial atrophy; this is limited to the glands themselves, and is specially shown at the 
free ends. Under high power cloudy swelling and degeneration of the base and nuclei can be 
seen. Hematoxylin and eosin. X 100. 



GENERAL AND OSTEOPATHIC. 411 

We commonly think of motor and sensory spinal cord centers 
as being separate and distinct; such is true to a limited extent 
only, for both are interdependent. Other so-called spinal cord 
centers are vasomotor, viscero-motor, reflex, etc. All are part 
and parcel of interdependent functions and all en masse are 
essential to the body unit.* 

So in a strict sense there is no such thing as an independent 
organ, pictured from the viewpoint of an entity. The vasomotors 
and viscero-motors and secretory fibers must under health con- 
ditions receive their full quota of nervous tension or impulses. 
The osteopathic lesion will disturb this balance, from all the evi- 
dence, just as quickly as the sensory or motor balance, but not 
being related to so-termed sense organs directly, we are less con- 
scious of the disturbance. Consequently, in all and through all, 
sensory, motor, vasomotor, viscero-motor, etc., must we look 
for the beginning pathology. 

As has been intimated, nerve centers are partially grouped 
anatomically as well as functionally due to evolutionary changes, 
but each segment is only partially an anatomic and functional 
center. The segments above and below enter anatomically, 
more or less, into direct relations whether we are considering 
spinal cord proper, posterior spinal ganglion, or sympathetics. 
Herein is suggested to a certain extent the key to characteristic 
osteopathic technique. Our work is to adjust specific anatomic 
lesions, that is, lesions of gross structural perversions (mechanical), 
whereby nervous tension has been more or less partially blocked. 
The majority of these lesions in order to specially affect a certain 
organ will be found within a certain area because within certain 
segments (not commonly a single one) are grouped anatomically 
the various centers functionally related to the organ. This must 
not be interpreted too literally for it is all due to a more or less 
definite change, as heretofore stated, arising from evolutionary 
forces. Thus segments are partially independent but all over- 
lapping most intricately and all grouped together most complexly 
to form a unit. Vasomotor and viscero-motor centers so far as 



"Hill, "The Body at Work. " 



412 PHYSIOLOGY : 

organic life is concerned give rise to the nervous-center idea, owing 
to their great importance and to the definite change produced 
by way of the reflexes when corresponding segments, afferent 
fibers, are stimulated. True osteopathic technique is neither 
mechanical stimulation nor inhibition of nervous tissue. Re- 
lease the osteopathic lesion by adjustment and the quiet, perma- 
nent and imperceptible stimulation, nervous tension or balance, 
or tone, will be forthcoming — and this is osteopathy. Specific 
technique is specific adjustment, wherever indicated, nothing 
more or less; wherein the rigidity, the immobilization, the sub- 
luxation is reduced by mechanical means and nervous balance 
established. Indiscriminate " stimulation, " " manipulation, " and 
"general treatment" is almost certain to defeat specific purposes, 
for in the first place it is not indicated, and secondly reflexes nor- 
mally intact are disturbed at the expense of the already labored 
reflexes of the lesion.* 

A FEW GENERAL PRINCIPLES. 

Whatever the character of a nerve stimulus, there is always 
a chemical and physical change in the environment of the nerve 
cell. And this change or activity is propagated through the 
protoplasm of the neuron. Much, therefore, depends upon 
the integrity of all parts of the nervous element, its functional 
and structural relations, as well as the basic nutritive supply. 

It is interesting to note that the neuron may function for a 
time without a cell body, but as soon as the nutrition of the proto- 
plasm is utilized, function ceases and the nerve element dies. 
We must remember two fundamental facts : that an intact nerve 
cell (structurally) and that both functioning receptive and exci- 
tatory cells are absolutely essential to the health of the organism. 
Associated with this are the facts that " structural differentiation 
of the cell is correlated with a functional polarity, " and that 
the process which receives the impulse " corresponds in form 
and time of development to a cell of the usual form. " 

*See Abrams, " Spondylotherapy, " p. 8. 



GENERAL AND OSTEOPATHIC 



413 



Another point we should keep clearly in mind is that a nerve 
element is not an entity. Within all probability every cell^and 
group of cells are dependent to a greater or less extent upon the 
intactness of the body mechanism. A cell may be termed a struc- 
tural and functional unit of any organ, but it is the organ or organ- 






(■♦' 




W 



y :./ 



w 



Fig. 59. 
X350. 



-Acute catarrhal inflammation of the intestine (ileum). Hematoxylin and eosin. 



ism complex that is of special specific significance, although every 
part of the protoplasmic mass is an essential. But it is the func- 
tioning en masse that is of particular significance. Thus has 
arisen the partially true statement that a neuron is independent 
only from a trophic viewpoint. Osteopathically (readjustment) 
we are daily taught by the clinical point of view that the various 






414 PHYSIOLOGY : 

nervous mechanisms and systems and correlations are specific 
only within certain limitations; that afferent impulses are essen- 
tial to functioning; that elasticity, flexibility, mobility, of the 
skeletal tissues means health, vitality, life; that afferent impulses 
are not necessarily all sensory ones; that readjustment, not mech- 
anical stimulation and inhibition, is the one essential to osteo- 
pathic technique; and that technique is diametrically opposed 
to any routinism, but is specific mechanical adjustment of minutiae 
as well as of the grosser tissues. 

To the physiologist and pathologist a knowledge of the func- 
tional systems is necessary, for the various pathways of the nerve 
elements are shaped and decided both by the inheritance and 
experience of the individual. To the practicing osteopath all 
of this is of importance, but the one essential beyond others is 
to understand anatomical mechanics and architecture — to practice 
adjustment. 

FUNCTIONAL DIVISIONS.* 

We know that all action externally or internally is the re- 
sult directly or indirectly of stimuli, and that given certain stimuli 
distinct and characteristic response will follow. This is true 
of all nervous activity, whether the change relates to the external 
world or has to do with internal nutritive processes. 

Consequently we consider, morphologically, for convenience 
somatic and visceral divisions, the former dealing with the external 
surroundings and being divided into afferent and efferent divis- 
ions. The latter, being concerned largely with the viscera, is 
also divided into afferent and efferent divisions. 

These divisions, somatic afferent and efferent, visceral affer- 
ent and efferent, are fundamental both structurally and func- 
tionally, and with exceptions the four kinds of activities, "the 
reception of somatic stimuli, the direction of somatic movements, 
the reception of visceral stimuli, the direction of visceral activities," 
"are called for in all segments of the body, and consequently 



*The data in this and the succeeding section has been largely taken from Johnston's 
"Nervous System of Vertebrates." 



GENERAL AND OSTEOPATHIC. 



415 



-each of the functional divisions is represented in each segment 
of the body, and all the segments of a given division are serially 
homologous with one another. " This is of special interest to the 
osteopath when considering the importance and significance of 
the osteopathic lesion to visceral disorder. We know that vaso- 
motor control, visceral muscular tone, and secretory activities 
constitute an important part of visceral integrity. To what 
extent the somatic stimuli are contributing factors to these visceral 
activities and consequently nutrition is of great significance in 
discussing the relative import of the osteopathic lesion as an 
etiologic factor. 




<~*&H**c* 



n^Ok'%: 



&*•!** V&fc"- • '.<- - ,. ; Oft fetsssn?- 



/* • r A 






Fig. 60. — Passive congestion of kidney. Engorged vein and slight cell infiltration. Every 
animal with lesions from eleventh to thirteenth dorsals presented congested and inflamed 
kidneys. Urine analysis before and a few days after lesion production supported the osteo- 
pathic lesion theory. Hematoxylin and congo red. X 110. 






416 • physiology: 

Somatic Afferent. — We will sketch a few points bearing 
upon the several functional divisions. The first division, the 
somatic afferent, referring to the cutaneous nerves will answer 
our purpose. These form a large part of the dorsal spinal nerves 
of the trunk, the section of the body we have experimented with. 
However, the same principles will be applicable elsewhere as 
here. These fibers have their ganglion cells in the spinal ganglia. 
The distal ends are found between the cells of the epidermis and 
consist of free branches. From the ganglion cells the central 
fibers pass into the dorsal part of the cord and bifurcate. One 
branch, the longer, extends upward and the other downward, 
ending finally in the dorsal horn; these fibers form the dorsal 
tracts. Each branch gives off collateral branches, some to one 
side of the cord, others to the opposite side, while still others pass 
to the ventral horn and to other areas. Thus it is readily seen 
that there is a basis for a great variety of reflexes, the simplest 
being with collaterals to the ventral horn. 

Visceral Afferent. — The visceral afferent division is much 
smaller than the cutaneous afferent system. These are the fibers 
that bring impulses from the viscera to the spinal cord and 
brain. Johnston says: "They are distributed to the mucous sur- 
face in much the same way as the general cutaneous fibers of the 
skin. In the absence of special knowledge as to their appropriate 
stimuli it may be supposed that the fiber endings are stimulated 
by pressure as are the general cutaneous endings. Although it 
would be confusing to apply the term tactile to visceral impulses, 
it is probable that there is a close analogy between the two. 
The difference between cutaneous and visceral sensory apparatus 
is not in the form of the endings or the mode of stimulation, 
but in the connections of the two kinds of fibers in the central 
nervous system." The above is of more than ordinary osteo- 
pathic interest. If the osteopathic lesion ranks a very important 
etiologic factor, as we think it does, the relation and connection 
of the various functional nervous divisions both as to impulses 
and nutritive supply of is primary and fundamental consideration. 




V Arterial anasl osis; B, intercostal artery; C, venous anastomosis; D. intercostal vein; E, spinal cord; F, antero-median arterv; 

' P ' ! ■■■ " H, ganglion on post- r , I, spina! cord; J. yanclion on post, root; K, thoracic duct; L, vena azygoa minor superior; M, supi>i U>\ ■.■..-!... 

" "^ ' ' ' li":i i, ..■!!! . \, si.'llni.- Imanicnt; (>, intercostal vein, artery, nerve; P, rami coruniunieantcH; (), vena azv«f.s minor mL-ri-.i , R, -real splanchnic: 
>. ]:iirr;tl eliam nantilia; T, intennstal arterv. 



GENERAL AND OSTEOPATHIC. 417 

" These visceral afferent fibers form a component of each 
of the dorsal nerves of trunk." Their ganglion cells are in the 
posterior spinal ganglia. The white rami conduct the fibers to a 
sympathetic ganglion and then by way of the sympathetics to the 
viscus. Clarke's column, which is in a mesial position to the 
base of the dorsal horn, contains the central endings in the cord. 
The neurites from the cells of this column constitute the 
direct cerebellar tract. Some of the fibers of the visceral afferent 
have other central connections, but the bifurcation and tract 
formation is not so marked as in somatic afferents. Of course 
an important relation here is that with the viscero-motor reflex. 

Somatic Motor. — These nerves arise from the cells of the 
ventral horn. They pass from the ventral surface of the cord 
and form the anterior fibers of the spinal nerve. The ventral 
nerve unites with the corresponding dorsal nerve near the distal 
end of the ganglion of the dorsal nerve and thus is formed the 
composite spinal nerve. Division of the spinal nerve into dorsal 
and ventral rami takes place. Near this point the ramus com- 
municans passes to the sympathetic. 

The central endings of the somatic nerves are in the latero- 
ventral area. The cells as well as the dendrites are large and the 
latter cover a large territory. A number of the neurites pass 
through one or more segments, before making their exit. Somatic 
motor fibers and their collaterals in the central nervous system 
are extensive, for bodily movements is an important function. 
Between the cutaneous surface and somatic motor nuclei there is 
a direct connection. The connection with these motor nuclei 
and visceral sensory is not supposed to be so direct; further in- 
vestigation is required. But the motor neuron includes an im- 
portant field for stimuli from many sources and bears direct or 
indirect relation to movements of the body. 

Visceral Efferent. — The visceral efferent fibers arise from 
nuclei in the lateral horn and pass out by way of the ventral roots 
through the white rami into the sympathetic ganglia. Probably 
visceral afferent collaterals directly connect with the visceral 
efferent nuclei. The correlation of the somatic and visceral 



418 



PHYSIOLOGY : 



functions is not understood. There are different tracts and dif- 
ferent nerve centers. 

The visceral efferents supply the smooth muscles and glands 
of the body by way of the sympathetics as well as the muscles of 
the heart and blood vessels. 




Fig. 61. — Hemorrhagic inflammation of the kidney tubules. In addition to the hem- 
orrhagic areas beginning cellular degeneration is readily noted. Hematoxylin and eosin. X 110 

The great osteopathic lesson to be learned from this brief 
resume of nervous anatomy is twofold: First, although to a 
certain extent, both structurally and functionally, the nervous 
system is partially separated into divisions, there is an absolute 
dependency of one part to the other to stimuli. These impulses 
are part of the continuous life of the individual and each division 
is an absolute essential to every other division, both structurally 



GENERAL AND OSTEOPATHIC. 419 

and functionally. This is shown by both external and internal 
environment as well as by the morphological construction. Em- 
bryologically the sensory and motor fibers, the glia, the neuroglia, 
the sheath of Schwann as well as the different nuclei are all inter- 
dependent. Impair one portion even functionally and all of the 
others, to a great or less extent, are impaired. 

Secondly, nutritively there is even a greater significance to 
the point that one part is dependent upon others. Although 
trophically the neuron is termed an independent structure, still 
this is a fact only when nutrition is intact and impulses are normal. 
One of the most important facts of anatomy is to note the grouping 
of nuclei and the forming of ganglia and to study how absolutely 
dependent their integrity is to intact circulatory environment. 
Their circulatory dependency can not be subdivided into parts, 
more or less independent, as their* functions are divided, for a 
group or ganglion may as a whole be to a greater or less extent 
impaired by the disturbance of a single vessel. This is a point, 
we believe, that can not be too greatly emphasized, for its bearing 
upon osteopathic technique is most significant. 

THE SYMPATHETIC SYSTEM. 

Embryologically the sympathetic system has the same origin 
•as the cerebrospinal system, which explains the intimate func- 
tional and pathological relations between the two systems. 

Its development, however, is later than the cerebrospinal 
system. It is an " outgrowth of fibers from the ventral root and 
also from the dorsal ganglion, in the direction of the aorta." 
This continued outgrowth of cells retains its connections until 
finally corresponding to each segment a pair of ganglia is formed. 
These are the ganglia of the chain and their connections are the 
rami communicantes. Later the ganglia are connected longi- 
tudinally; also additional ganglia are formed. Thus are formed 
the pre-vertebral ganglia, and still a little later the cell migration 
forms the peripheral ganglia, such as the ganglia of the heart 
and digestive canal. While the above is taking place some of 



420 PHYSIOLOGY : 

the cells of the ganglia of the chain and probably of other ganglia 
"send fibers back along the rami communicantes into the spinal 
ganglia or the rami of the spinal nerves. " These fibers are called 
the gray ramus communicans. The fibers which grow out from 
the spinal nerves in time become myelinated and consequently 
are called white rami communicantes. 

Thus the important feature to be noted here is that there is 
an intimate anatomical connection between the ventral root and 
dorsal root ganglion outward to the ganglia of the chain, the 
prevertebral ganglia, such as the cardiac, solar and hypogastric 
plexuses, and the peripheral ganglia, such as the small ganglia 
of the heart and Auerbach and Meissner plexuses; and then 
connection back again to the spinal ganglia or the rami of the 
spinal nerves by way of the gray rami. 

Osteopathically this anatomical relationship is of the greatest 
significance. It enters into the everyday consideration of the 
practitioner. Experimentally we have found that all the ganglia, 
including those of the cord to chain ganglia, are subject to patho- 
logic changes due to the osteopathic lesion.* 

Reference to a few more anatomical relations will probably 
help to elucidate this problem, although a few of the nervous 
connections were mentioned in the previous section. 

The visceral sensory fibers have their ganglion cells in the 
spinal ganglia. These "are the largest of the myelinated fibers 
running in the sympathetic nerves and may be seen to pass through 
one or more of the sympathetic ganglia without forming any 
connection with the sympathetic cells." The distribution of 
the nerves is in the mucosa of the viscera. The central ending 
is in the visceral sensory column of the cord. Thus it is seen 
that these fibers are not really a part of the sympathetic owing 
to their not being anatomically connected. This fact can not 
have other than an important consideration in explaining etio- 
logically the relation of the osteopathic lesion to visceral disturb- 
ances. It is claimed that these fibers "are older than the sympa- 

*Morat, speaking of the general laws of Waller, says: "They may be verified in all nerves, 
in the tracts found in the spinal column and in the brain and the great sympathetic system. " 
See section, this article, "Changes in Nervous Tissue." 






GENERAL AND OSTEOPATHIC. 



421 



thetic system and that the sympathetic ganglia are placed along 
the course of these primitive visceral sensory fibers." 

Then there are small myelinated efferent fibers from the cells 
of the spinal cord that pass out by way of the ventral roots. They 
enter the ganglia of the chain and end in the first ganglion, or 




Fig. 62. — Acute parenchymatous goitre produced by the osteopathic lesion. Some of 
the colloid spaces are nearly normal; others show change from cell proliferation. Hematoxylin 
and eosin. X 75. 



422 PHYSIOLOGY : 

pass through it to another ganglion, or end in a prevertebral 
ganglion, or a peripheral ganglion. When passing through one 
ganglion to another they may give off collaterals. These fibers 
end by piercing the capsule of the sympathetic cells, ganglia of 
the chain, prevertebral and peripheral and form pericellular bas- 
kets; so that " impulses sent out from the central nervous system 
are transferred to the sympathetic excitatory cells." Thus, 
probably, "the great majority if not all of the excitatory cells 
of the sympathetic are thus brought under the direct influence 
of the central nervous system." Consequently it is readily 
seen that this type of nerve element of the sympathetic is also an 
important factor for osteopathic consideration. 

Another type of nerve element that goes to make up the 
structure of the sympathetic system is sympathetic excitatory 
cells. Their structure has much in common with nervous tissue 
elsewhere. They may or may not become myelinated, but the 
fiber is very small. These are fibers that innervate all smooth 
muscle of the " alimentary canal, the ducts of glands, the urino- 
genital system, blood vessels, the skin or the eye. " 

The fourth type is the sympathetic sensory cells. These 
are found in the peripheral ganglia and have long dendrites 
that "are supposed to be distributed to mucosae and serve as 
sensory fibers. " They give off branches where they pass through 
the sympathetic ganglia. 

Enough anatomical data has been given to serve our purpose, 
that "the afferent and efferent neurones whose cell-bodies lie 
respectively in the cranial or spinal ganglia and in the brain or 
cord belong properly to the cerebrospinal system and not to the 
sympathetic," so that "in a strict sense the sympathetic consists 
solely of the neurones whose cell-bodies lie in the various ganglia, 
the excitatory and sensory sympathetic cells. " Visceral activities 
is the cause of this off-shoot of the visceral afferent and efferent 
divisions of the nervous system. The off-shoot is really an inter- 
polation "in the efferent limb of the reflex chain of a peripheral 
neuron between the cerebrospinal fiber and the organ innervated. " 
There is comparatively little independence, peripheral reflexes, 



GENERAL AND OSTEOPATHIC. 423 

o: the sympathetic system. "The great majority of its actions 
are directly aroused by efferent impulses coming from the brain 
or spinal cord and in response to the stimulation of visceral sensory 
fibers which run through, but have no connection with, the sympa- 
thetic ganglia." Hence an important part of the osteopathic 
lesion pathology must be based upon this last statement. This 
factor must lie within the findings, pathologically, of the cerebro- 
spinal ganglia. Anything that disturbs their impulses or nutrition 
must be basic* 

IMPORTANT VASCULAR CHANGES. 

Within all probability the chronicity of the pathology follow- 
ing the osteopathic lesion is dependent upon nutritive disturbance, 
first of the nerve cell, and secondly of the vascular tissues. To 
what extent the mere blockage of local afferent fibers produce 
serious and long sustained functional disturbance and structural 
involvement would probably be debatable.! Consequently 
we are obliged to look for deeper and more significant factors. 
Although irritation or blockage or disuse of certain afferent fibers 
must have a deleterious effect, inceptively, upon its dependent 
reflex arcs, the remaining predominating tissue concerned with 
metabolic changes is the vascular system. And likewise with 
the vascular system as with the nervous system the problem 



*In this slight sketch we have said nothing about the bulbar autonomic system, the impor- 
tance of the vagi and glosso-pharyngeals, stellate ganglion, etc., or the sacral autonomic system. 
Our purpose is to present an outline picture only, of the basic points of osteopathic pathology. 
We especiallv refer to Quain's Anatomv, Vol. Ill, eleventh edition, and Oppenheim's text 
book, Vol. II, fifth edition. 

fPorter in Harvey Lectures, 1906-07, under "Vasomotor Relations," says: "The mal- 
adjustment between afferent and efferent impulses is the source of many ills in our modern 
life." "The vasomotor system seldom if ever dilates or constricts all the vessels at one time. 
The same afferent impulse will cause the vasomotor center to dilate the vessels of the face 
while it constricts those of the abdomen. The effect upon the general blood pressure depends 
upon the relative size of the dilating and constricting areas. Here the splanchnic nerves, 
which govern the vessels in the abdomen, have great importance." "The more the circula- 
tion is studied, the stronger is the conviction that it is not a fixed state, but a sensitive equili- 
brium, the result of the constantly varying action of a great number of factors." A great 
clinical fact is constantly presented to the practitioner: There are comparatively few healthy 
individuals; and the diseased ones present an innumerable variety of osteopathic lesions, which 
upon an adjustment with a regulation of habits works a wonderful change in the health of the 
individual. Vessel dilatation must play an important role. Vasomotor spasm and paralysis 
induced by the osteopathic lesion is certain to lower resistance. Also Moral's "Physiology 
of the Nervous Svstem, " Oppenheim's, "Nervous Diseases," Vol. 1, p. 124; Am. Jour. 
Phys., Mch., 1911; McConnell, "The Vasomotors," A. O. A. Jour., Mch., 1912. 



424 PHYSIOLOGY : 

must be approached from both the anatomic and physiologic 
sides. 

The osteopathic lesion as an initiatory factor is an anatomic 
condition — a structural perversion — and no matter from just 
what points or physiologic phases the inception arises, certain 
definite pathologic changes are noted as a consequence. Just 
what proportion of this inceptive role the disturbance of afferent 
impulses play, further physiologic experimentation can alone 
determine. Consideration of the afferent vasomotor reflex will 
probably throw considerable light on the problem. But mere 
anatomic perversion — subluxation, rigidity, etc. — must also, 
by virtue of its disturbance of anatomic structures injure or damage 
or disturb circulatory integrity. Nervous tissue is very sensitive 
to circulatory changes. Mere compression of the abdominal aorta 
for from fifteen to forty-five minutes will produce temporary 
paraplegia. If the compression is kept up for an hour or more, 
permanent paraplegia is the result. The degeneration in these 
cases is confined to the gray matter and in its connecting tracts, 
while the spinal ganglion and pyramidal tracts are not affected. 

It is the vascular changes of a character approaching in- 
flammatory phenomena — the dilated veins and capillaries, 
the slowed blood stream, the endothelial compromise, the plasma 
leakage, leucocytal invasion, and diapedesis — that are of great 
significance, for when these changes occur in the nervous structures 
dependent nervous tissue must degenerate. Whether the vascular 
change is brought about by direct vascular pressure or disturbed 
afferent impulses by way of vaso-constrictors the significance 
of the pathology speaks for itself. (And it should always be 
remembered that nerve tissue has a very rich blood supply.) 
If the vasomotor centers are automatic only, deep-seated struc- 
tural perversion affecting the circulation of these centers alone 
would answer;* but late physiologies teach that probably the 
centers are not automatic. (See first foot note under Chapter 
XLV Practical.) Experiments show that the field of vascular 



*See McConnell, "The Vasomotors," A. O. A. Jour., Mch., 1912; "Osteopathy in the 
Light of Evolution," A. O. A. Jour., May, 1913. 










/ 



Plate XXXI.— A, Aorta; B, vena azygos major; C, lateral chain 
vein; E, great splanchnic; F, anterior common ligament. 



ganglia; D, intercostal 



GENERAL AND OSTEOPATHIC. 425 

circulation to the different segments is comparatively extensive 
and that within all probability the serious or predominating lesion 
is to the nutritive supply of the ganglia.* 

The above phenomena that approaches the pathology of 
inflammation is probably basic of many disease changes, whether 
in nervous tissue or other tissue or viscus, for nervous and vas- 
cular structure are both predominating structures. Thus the 
osteopathic lesion may be both a predominating lesion (lowered 
resistance) or an active lesion. " Inflammation is the process by 
means of which cells and serum accumulate about an injurious 
substance and tend to remove or destroy it;"f but an injury 
may be mechanical, chemical, thermal, or bacterial. And the 
injury may show various nervous phenomena and be situated a 
long way from special influence of nervous centers. But we 
are of the opinion that the above, features are a basic outline 
explanatory of an important part of osteopathic pathology. 

One point further: Although " inflammation is the reaction 
which follows an injury affecting the walls of blood vessels; in- 
creased permeability facilitates the escape of plasma and cor- 
puscles into the surrounding tissue, " bacterial infection is not 
the only cause, for "an immense number of sterile substances, 
both fluid and solid, soluble and insoluble, organic and inorganic, 
incite a reaction which differs in no essential respect from that 
which follows the invasion of micro-organisms. "J This would 
seem to teach us that a fundamental law of nervous physiology 
is that a nervous equilibrium represents a fluctuating vasomotor 
balance dependent upon either, or both, afferent tone and nerve- 
cell nutritive integrity. Muscular contracture, spinal rigidity, 
vertebral subluxations, a displaced viscus, or a foreign body 
effect fundamentally nervous tissue and vascular structure after 



*"The arteries in the brain and spinal cord are end-arteries; that is, are vessels whose 
branches do not anastomose with those of neighboring arteries, but break up into capillaries 
continued in the veins. Martin's General Path. See also Oppenheim. 

tOpie-Harvey Lecture on Inflammation, Feb., 1910. See also Martin, Gen. Path. ; Tt.onia, 
Gen. Path. The nervous system we have taken for granted may be disturbed by other causes 
than osteopathic, e. g., heredity, infection, auto-intoxication; but in these the osteopathic 
lesion is undoubtedly often a factor. 

tOpie-Harvey Lecture, 1910. 



426 PHYSIOLOGY 






the same manner. Local congestion of any part of the body 
produces phenomena basically of the same character. But the 
locality of the lesion may be most significant, e. g., the spinal 
osteopathic lesion being contiguous and in fact not only environ- 
ing but dynamically penetrating most important structures. Thus 
must not only engorgement, ischemia, altered blood state and 
various tissue changes play their role. Likewise adhesions, 
contractures, and various stages of chronicity play a subsidiary 
role to a vertebral lesion. The locality and character of the gross 
anatomic change to the finer and far-reaching histologic distur- 
bances are innumerable.* 

CHANGES IN NERVOUS TISSUE. 

One of the most significant phases of osteopathic pathology is 
to be found in disturbed vascular supply to the nervous tissue. f 
Judging by our experimental findings (microscopical), the nutri- 
tive changes in the ganglia must be paramount. Starting from 
the ever constant fact that nervous tissue is unusually well supplied 
with nutritive vessels, any change in these vessels would seem 
significant. And these changes, dilatation, serum leakage, etc., 
have been repeatedly noted. The ganglia from cord to sympa- 
thetic are unquestionably affected. 

The ecchymoses, diapedesis, cellular atrophy, and neuron 
degeneration can have but one interpretation, especially when 
concomitant with, and anatomically related to, the perverted 
tissue (osteopathic lesion) and concurrent visceral functions are 
disturbed, that the osteopathic lesion is a vital part of etiology. 

The restriction of a blood current to a part is of primary 
importance and particularly so when nervous tissue is concerned. 
Morat speaks of three orders of nervous degeneration, Wallerian, 
ascending, and atrophic. Osteopathically, we believe, it is the 



*But in all the maze of histologic, physiologic and pathologic data, we must not lose sight 
of fundamentals, for if the osteopathic lesion does not fill an important gap in etiology or phe- 
nomena basic to perverted physiology the osteopathic lesion is comparatively an insignifi- 
cant factor. 

t Research Bulletin No. 1, "The Osteopathic Lesion." 



GENERAL AND OSTEOPATHIC. 427 

atrophic order of degeneration that invites special consideration; 
not necessarily " through prolonged default of functional activity, " 
but through definite and active pathological changes dependent 
upon vascular disturbance. This reveals to a certain extent a 
new pathology, not that " a vascular dilatation followed by dia- 
pedesis and leucocytal invasion" is a newly discovered condition 
to an extensive pathology, but we believe this is a "new path- 
ology" as interpretation in so far as study of the osteopathic 
lesion has revealed. 

That there is a certain basis for this pathology, other than 
osteopathic, medical literature shows. We would refer to Oppen- 
heim, Vol. I, pp. 109, 269, 395; Vol. II, pp. 1163, 1172. He 
also cites an interesting point, p. 1313: "It has been long since 
shown by clinical observations that a disturbance of vasomotor 
innervation leads in the end to degenerative changes in the vessel 
walls. "* 

SUMMARY. 

Two or three features of the nervous system, broadly stated 
are fundamental to an understanding of the osteopathic lesion: 

(a) Co-ordination of the innumerable activities dependent 
upon both external and internal environment. Internal bodily 
activities initiate changes as well as external activities, and con- 
duction and co-ordination of these impulses constitute the "bio- 
logical significance of the nervous system." Osteopathically, 
the structural and functional unification of the different segments 
constitutes the anatomical and physiological basis of the lesion; 

(b) There are various kinds of "sensory" stimuli, whether 
from external or internal sources. The several afferent fibers 
are simply limited to the character of stimulus necessary to initia- 
ate an impulse. A structurally intact fiber is the first essential 
to health, while a constantly functioning fiber in response to its 



*For supplementary reading consult Bevan Lewis in Allbutt System of Med.; Meigs, 
"Origin of Disease;" MacKenzie, "Svmptoms and their Interpretation;" Research Bulletin 
No. 1. ... 

An interesting series of articles by Solis-Cohen bearing on angio-neurotic conditions will 
be found, "N. Y. Med. Jour.," Feb/l9, 26 and Mch. 5, 1910. Angio paralysis and angio 
spasm are undoubtedly an important part of pathology. 



428 PHYSIOLOGY I 

characteristics, whether from immediate or reflex sources, com- 
pletes its purpose. We should not lose sight of the fact that all 
nervous phenomena from special functioning to bodily tone are 
unequivocally dependent upon the so-termed reflex changes. 
Keeping in view the basic point that all nervous response is 
absolutely dependent upon the afferent fiber, reflex arc, and 
efferent fiber, will be most valuable when discussing nervous struc- 
ures more or less arbitrarily " specialized " and " differentiated"; 

(c) "The superiority of the nervous system of man does not 
consist, in the main, of superiority in sense organs or motor appara- 
tus, but in the enormous development of the intermediate neuron 
system." (Some of our data here is derived from Bailey and 
Miller's Embryology.) 

These intermediate or central neurones mediate between 
the afferent and efferent neurones. This increases the complexity 
of the nervous system by associating all kinds of stimuli, adding 
complicated combinations and extensive co-ordination. There 
is a vast difference in the complexity of a two-neuron reflex arc 
and a three-neuron reflex arc. In the human brain the special 
distinguishing feature is the association neurones. Thus evolu- 
tionary change is not so much a segmental one as it is a develop- 
ment of the associating mechanism. An important consideration 
here is that data derived from animal experimentation is reliable 
and applicable to all vertebrate nervous systems. 

A striking and significant point in the highly developed ner- 
vous structure is the concentration, centralization, and fusion of 
the nervous tissues by increase of ganglionic structure and asso- 
ciation fibers. This is early initiated in the embryo by the for- 
mation and closure of the neural tube. Among other changes 
in the morphology of the afferent and efferent neurones, there is 
brought about a certain physiological dependence of the internal 
(visceral) and external (somatic) structures, although the inter- 
polation of neurones in the autonomic system represents a certain 
independence. However, the cord sends efferent fibers to both 
somatic and visceral structures, and within all probability the 
integrity of a segment is dependent upon all incoming stimuli 
of its own as well as contiguous segments. There may be a certain 



GENERAL AND OSTEOPATHIC. 429 

amount of physiological dependence, still the intersegmental neu- 
rones are an essential to group and higher functioning. 

In the osteopathic lesion (pathology) we should keep in 
mind the fact that the changes are more segmental in character 
rather than always showing a very definitely localized point of 
obstruction. Reflex activity is the basis of physiologic function- 
ing, and the several segments are in reality a series of reflex arcs. 
Whether inceptive pathologic changes are, like the vertebral osteo- 
pathic lesion, contiguous to the central nervous systems, or are 
brought about by a duodenal ulcer or adherent appendix, the 
nervous involvement is expressed through the reflex arc. No 
matter how specialized the nervous structures may be, there is 
basically a dependent reflex change as well as a greater or less 
widespread disturbance of nervous equilibrium. 

Nervous equilibrium is not alone a localized phenomenon, 
but instead a generalized one, as expressed, for example, in the 
nutrition, tone, and neuro-muscular balance being dependent 
in its greatest efficiency upon all afferent fibers, reflex arcs and 
efferent fibers. Even the innervation of a single skeletal muscle 
comes from more than one segment or the intestinal motors may 
be blocked from more than one point by either central or peripheral 
lesions. Normal impulses, free circulation (arterial, venous, 
lymphatic), and sufficient oxygen are fundamental to metabolism. 

Embryology, histology, physiology, pathology, and experi- 
ment have all contributed to a partial understanding of function 
and perverted function, but the greatest of pathological results 
medically have been a noting of effects and not of causes, in so 
far as the innumerable disorders and their infinite gradations are 
concerned. 

Nervous and vascular tissues are master tissues, hence, 
logically we must look to these tissues, for the inceptions of bodily 
ill health. Fundamentally, anything that impairs these tissues 
will be reflected upon their dependent parts, and the importance, 
physiologically, of the tissue or organ involved (e. g., kidney) 
will further determine the character and gravity of the secondary 
changes. Here, however, we are specially interested in the in- 
ception and immediate effect of the osteopathic lesion. 



430 PHYSIOLOGY I 

EQUILIBRIUM AND HEALTH. 

Before one discusses the nature of ill health, some sort of 
health standard should be instituted. Health from the stand- 
point of nervous functioning is dependent upon a stable equilib- 
rium; this means not only uninterrupted nervous conduction, 
but sufficient nervous impulses. Likewise, in vascular function- 
ing, the flow must not only be unimpeded, but it must be sufficient 
and continuous. In other words, physiologic equalization is 
the fundamental requirement. 

Probably neither physiologists nor clinicians have sufficiently 
emphasized the necessity of the afferent impulses, whether so- 
termed " sensory " or others, that constitute the basis of all nervous 
activity. Every movement, exercise, work, recreation, air cur- 
rents, respiration, alimentary activity, vascular propulsion, bath- 
ing, environment, has its effect upon afferent innervation, in fact, 
is basic to so-termed hygiene. 

The principle of the summation of stimuli is well exemplified 
here, and constitutes a fundamental principle of bodily health 
and development. (And it also constitutes an important part 
of pathology.) The effectors must function continually and 
regularly in order that the receptors may execute their part. In 
order that the body may work as a concatenated whole, every 
part must fulfil its requirements. Herein, in our opinion, is the 
basic point to osteopathy. Given an osteopathic lesion, whether 
osseous, muscular, or visceral, the first effect is one of nervous 
blockage. The activity, impulses, and rhythm of the local forces 
are at once disturbed so that both local and correlated tissues 
are impaired, dependent upon their character and specific func- 
tions. A twisted vertebra, rib, or innominate will have no differ- 
ent effect, basically, as has been stated, than an adherent retro- 
verted uterus, a fibroid degeneration of the appendix, or a broken 
plantar arch although the location and relation of the vertebra 
to the central nervous system are of vastly greater impeding 
significance. 



GENERAL AND OSTEOPATHIC. 431 

ANATOMIC AND PATHOLOGIC CHANGES. 

Anatomical perfection (structurally) is the basis of health 
from a characteristic osteopathic viewpoint, for this implies per- 
fect nervous and vascular functioning, provided hygienic measures 
are carried out (although upon a broad biological basis function 
precedes structure, and practically physiologic activity and mobility 
is the health criterion) . It would be beside the point, as we view 
it, to always look upon the osteopathic lesion as some specific 
or individualized lesion of the nervous system alone, as for example, 
degeneration of the posterior column in tabes dorsalis, or degen- 
eration of the pyramidal tracts in early acquired spastic paralysis, 
yet this is the viewpoint of many when they insist (without any 
verified observation) that the pathology of the lesion follows 
pressure of the fibers at the spinal-foramen exit. If this were 
the case the pathology of the lesion would be a comparatively 
simple matter. No one will question but that such a condition 
may occasionally be found, or that very serious consequences 
may not follow, but we believe that the field is fundamentally a 
much broader one. 

Although the ligaments to a large extent maintain the chronic 
lesion (anatomically) it is the circulatory derangement, impover- 
ished nutrition, that maintains the pathologic changes. Whether 
part or all of the vascular pathology inceptively is due to seg- 
mental strain or stress en masse, or the result in part or as a whole 
of nervous blockage, resultant anemia, or hyperemia followed 
by edema and anemia of cord centers, sympathetic ganglia, and 
viscera are within all probability dependent upon nervous phe- 
nomena. Thus, taking the vertebral maladjustment as a type 
of an osteopathic lesion, the inceptive effect is a functional de- 
rangement in part, of the corresponding nervous segment. Upon 
a nervous basis alone, this is followed by either inhibition or 
stimulation (probably the latter at first), of involved nervous 
tissues. These functional derangements, if continued, are fol- 
lowed by organic changes. 



432 physiology: 

Organic change implies first a lessening of the nutritive in- 
tactness of the nervous element, either to lack of normal stimulus 
or traumatic damage, or to stress (mechanical) upon blood vessel 
or lymph channel; or, of probably greatest importance, upon 
involvement of vasomotors.* Following this further involvement 
and complication may arise, (a) infection, (b) toxins, (c) chemical 
changes, due to the lowered resistance. 

The location of the vertebral lesion is what makes the mal- 
adjustment significant. The central nervous system, more than 
any other tissue, is less resistant to circulatory impoverishment. 
Then general fatigue is an additional common factor frequently 
overlooked by the physician. A physiologic unit will be main- 
tained so long as the system is sufficiently energized, even if certain 
slight pathologic conditions are present. Forces that sustain 
one in health and ill health are largely of the same character, 
but vary greatly in degree as gradations of health conditions are 
initiated. 



^Relative to the theory of trophic nerves an instructive series of experiments will be found 
in the Am. Jour, of Physiology, Sept. 1, 1910, "The Rate of Healing of Wounds in Denervated 
Skin Areas and its Bearing on the Theory of Trophic Nerves," by Clara Jacobson with an 
addendum by Prof. Carlson. Among the conclusions are the following: "The results of the 
experiments reported indicate no diminution in the rate of healing of wounds in a denervated 
(sensory and motor) skin area as compared directly with that in a normal area." "It seems 
that so-called trophic disturbances may be due to vasomotor changes with increased suscept- 
ibility to infection or to the loss of protective reflexes from loss of sensitivity to injurious agents." 
Prof. Carlson adds: "I fail to see the possibility of this distinction (referring to Tschermak 
that there is no evidence for the existence of separate or specific trophic nerve fibers, but con- 
sider it highly probable that motor and sensory as well as afferent nerve fibers convey trophic 
impulses as an accessory function) between motor-sensory-tonic and trophic impulses in the 
same axis cylinder on the basis of our present knowledge or the advisability of retaining the 
term trophic for this conception. It seems to be true, in general, that moderate amounts of 
the special activity of organs are favorable to their metabolism and growth. The impaired 
metabolism and consequent atrophy in muscle, glands, and nerve centers following lesion of 
motor, secretory, and afferent pathways respectively can therefore be wholly accounted for 
as a direct result of the cessation of the special organ activity. " . . " The changes in muscle, 
gland, and nerve cells in consequence of lesion of or altered activity of conduction paths are 
probably the result of disuse or altered special organ activity. And the so-called trophic 
changes in the skin and epidermal structure can be accounted for by altered activity of the 
capillary cells in consequence of the hyperemia, increased pressure and possibly interference 
with secretory fibers." 



CHAPTER XLV. 
PRACTICAL CONSIDERATIONS. 

Adjustment is the magic coat of osteopathy. The condition 
of being adjusted is the essential quality that masters the secret 
forces of nature so that wholeness of the body is attained and 
maintained. To adjust is a law, for it represents a definite rela- 
tion between facts. And the clothing of the body with the law 
represents one of the fundamental factors of biology. 

Correction of the lesion, to adjust, is an accomplishment that 
requires considerable observation, experience, and practice. The 
art can not be learned in a day. Many factors, anatomic, physio- 
logic, and pathologic details, as well as judgment, enter into 
consideration. Basically the perceptive faculties have to be 
creatively changed in order to not only recognize the lesion but 
to interpret it; and this requires much time and conscious effort. 
As Poincare has emphasized in one of his books, " so-called correct 
perception is connected with a long-continued process of perceptual 
education, motived and initiated from within. " And this is just 
what the student so rarely appreciates. He is not willing to spend 
the time and effort and actual labor necessary to perfect himself, 
and the result is mediocre ability. He too often wilfully fudges 
the issue with a lot of hodge-podge methods at the expense of 
clean-cut therapy, and naturally the result is disappointing. 

Havelock Ellis wrote the following in reference to a certain 
scientific method. We quote it because it is so apropos to the 
method of osteopathic adjustment: a A scientific method is, 
strictly, an instrument. Its value depends upon the user." 
In adjustment we have an " instrument of great precision, but 
the best instrument in the world will not enable a man to select 
I his facts rightly or to interpret them correctly." Here is exactly 

433 



434 PHYSIOLOGY : 

the test-point in practical osteopathy — selection and interpreta- 
tion of facts. It is not only individual variation in every case 
and lack of experience that may prevent an accomplishment of 
desired and possible results, but after certain and sufficient data 
is secured the interpretation may be absolutely wrong. Then 
in addition to all this there is the art dependent upon tactile edu- 
cation, precision and co-ordination, that when perfected is the acme 
of the technicist's ambition. To him this is the means to the end 
of the joy of living; as Stevenson said, "to miss the joy is to miss 
all." 

Structure and function are most intimately inter-related. 
We believe that evolutionarily function precedes structure. Take, 
for example, natural selection, a factor of evolution, adaptation 
of structure is the principal fact or reality gained by the organism. 
The striving and expressing of function results in both changed 
and added structure. This, in our opinion, is of great biological 
significance. But in the field of disease where a very complex 
organism is structurally deranged the relationship between struc- 
ture and function is different; for here the osteopath comes to 
the aid of an organism that is either deranged structurally so that 
functional processes are impaired; or he harmonizes the environ- 
ment to the individual and short-circuits the process of evolution 
or reduces its effects to a minimum, so that the weakest has a 
greater chance to survive; or on the other hand he frequently 
harmonizes the individual to the environment,* as when he regu- 
lates the patient's daily regimen. Thus in the practical work 
of the healing art we consider structural integrity as basic, for 
we are dealing with problems of the moment and with the body 
as we find it, and not as the forces of applied eugenics and heredity 
may improve future generations. Our work is one of expediency. 
Although the functional test is the important one, structure must 



*We should appreciate that environment includes a very wide field (see Henderson, 
"The Fitness of the Environment")- "It is possible that the neurones possess some auto- 
matic power, i. e., some power of initiating nervous processes, as a result of changes in the 
fluids surrounding them. This automaticity, however, is not a prominent feature of the 
nervous system, which has been evolved as a purely reactive mechanism to the afferent impulses 
resulting from the material changes continually taking place in the environment of the animal. " 
(Starling, "Human Physiology.") See also, Sherrington, "The Integrative Action of the 
Nervous System. " 



GENERAL AND OSTEOPATHIC. 435 

• be intact before it can find complete expression or function. Here- 
in, then, arises the practical point in osteopathy — integrity of 
structure. 

We unhesitatingly place the so-called bony lesion as the 
prime consideration in characteristic osteopathic technique, for 
integrity of structure demands it. Morphologically and tech- 
nically the connective tissue constitutes the structural basis, 

I for both configuration of the organs as well as the body as a whole 
are conformed thereby, but later development chemically changes 
the density of the bones so that veritably they become the actual 
foundation of the mechanism. 

Intimately inter-related and associated with the bony struc- 
ture are the muscles and ligaments. The former are a fairly 

| stable but at the same time a quivering mass of organs that give 

; form and shape and support and litheness to the body, that 
brings about balance and stableness of the mechanism, and that 

J furnishes motive power and leverages for the several segments 
and members and the organism as a whole. Their structural 
and functional integrity is of the greatest importance in not only 
maintaining health, but are essential to the growth and develop- 
ment. We can not divorce one part of the structure without 
impairing or taking away something from another part or from 
the entire mechanism. It is the aggregate of structure and func- 
tion and their concatenation that makes the individual. In other 

| words every part must be intact and every function exercised 
before wholeness is attained. 

Associated with the bones and muscles and ligaments are 
the viscera which may be structurally deranged and misplaced 
and as a consequence create a train of symptoms that from an 
etiological viewpoint come under the category of the osteopathic 
lesion. Specialization of cell and organ has not altered the under- 
lying principle of adjustment (indeed, it has called for more pre- 

j cise attention), but has simply added to the complexity and in- 
tricacy of the organism. Exercise of function is the open sesame 
that unlocks the magic door of potentiality so that the forces of 
growth, development, and repair find expression. The comple- 



436 PHYSIOLOGY : 

ment of function from the angle of osteopathic technique is pre- 
cise adjustment of the anatomical parts in order to allow the 
necessary freedom of the forces. 

The practical interpretation of the lesion must not be con- 
strued as a peripheral blockage per se whether the periphery so 
far as the nervous system is concerned communicates with skeletal 
tissues, the digestive, pelvic, or respiratory apparati, or some 
other part, but in addition the blockage has a far-reaching and 
deep-seated effect, other than so-called nervous reflex, to the 
dependent metabolic processes, especially the ganglia of the 
central nervous system. If the factors that create and establish 
tone are dependent upon external, peripheral stimuli, and which 
stimuli may be applied even to abstract and non-spatial dealings 
of the mind,* the physiologic interpretation of the lesion is only 
a perversion of those processes due to an alteration of the circum- 
stances that normally contribute to establish tone; and clinical 
experience and experiment prove this to be the case. This is 
the practical significance and importance of the osteopathic lesion, 
and the niche it occupies in the etiologic field is far from a small 
one. 

OSTEOPATHIC CENTERS AND SPECIFIC TREATMENT. 

Probably considerable confusion and misunderstanding has 
arisen in our technique due to the association of the terms "osteo- 
pathic centers " and " specific treatment. " " Osteopathic centers 1 
has always been more or less a hazy term, based largely upon the 
location or rather aggregation of the so-called viscero-motor, secre- 
tory, and subsidiary vasomotor centers in the spinal cord, implying 
that by so-termed stimulation or inhibition or manipulation of 
certain spinal areas definite effects upon the viscera will be forth- 
coming. This idea, we think, has led to a misinterpretation of 
the so-called specific treatment or manipulation. Hence has 
followed with a number of osteopaths technique that is far from 
osteopathy and is nothing more or less than a " movement cure." 

*J. S. Huxley, "The Individual in the Animal Kingdom." 






GENERAL AND OSTEOPATHIC. 437 

Osteopathic centers are nervous centers. An interpretation 
of the latter term will clear up the former. Centers are nothing 
more nor less than an association and collection of neurones into 
a partial system in order to carry out certain systematic func- 
tions.* Thus there is both an anatomical and functional relation- 
ship and the aggregation of the gray matter is the greater when 
the demands are more complex or of a higher order. This co- 
ordination of functions really means functional or nervous centers 
not trophic. Embryology teaches us that there is a fusion of 
the segments of the gray axis giving origin to the functional asso- 
ciation. But the segments are neither entirely independent 
morphologically or functionally. Even a slight acquaintance 
of the relation of embryology to the closely interrelated spinal 

' cord and brain segments to the sympathetic shows this most 
clearly. And a study of the osteopathic lesion embryologically 

; considered, as well as a study of the experimental lesion, still 
further accentuates this fact. Hence the basis of the nervous 
system being made up of an aggregation of units of more or less 

j common and definite functions, but the functions of the several 
partial definite systems being graduated into others and all together 
comprising an independent whole. 

So far as locality is concerned, treatment can be " specific" 
to a certain point only — in just so far as one of these functional 

i units when disturbed by a certain lesion has its certain specific 
functions impaired, for an account of the dependency of these 
functional units one to the other the equilibrium of the entire 
system is disturbed. Now, owing to the probable general dis- 
turbance, to a greater or less extent, " specific" treatment does 
not necessarily imply the other extreme, a general body manipu- 
lation. This latter, alone, may defeat the entire purpose of the 
treatment; at any rate it precludes any definite osteopathic 
diagnosis. 

Specific treatment means specific adjustment — this is funda- 

*Morat states, "The connections which the different portions of the neuron gather together 
are centered in the nerve cell, whence the name 'trophic center' is given to the latter. In their 
turn the neurones associate and collect themselves together in more or less independent system, 
in 'functional centers' (or nervous, properly so-called)." See, also, Johnston, "Nervous 
System of Vertebrates." 



438 PHYSIOLOGY : 

mental to osteopathic technique. Without specific adjustment 
osteopathic etiology and pathology amounts to but little to the 
practitioner. Although the characterization and significance 
of osteopathy is based upon our interpretation of etiology, to the 
practitioner it amounts to but little if specific adjustment is not 
accomplished. Consequently specific treatment is not treatment 
of ''osteopathic centers" whether by so-termed " stimulation, " 
" inhibition, " or " manipulation " ; neither is it a " movement 
cure," "routinism" or "medical gymnastics." Specific treat- 
ment can mean nothing more nor less than specific readjustment 
of the osteopathic lesion; — and we know the osteopathic lesion 
is "any structural perversion which by pressure produces and 
maintains functional disturbances." Definite mechanical prin- 
ciples must be followed according to the individual case. This 
is characteristic treatment; and it requires most painstaking 
effort, for every case presents new problems to solve. 

All of this, however, does not preclude a certain amount of 
muscle relaxing or muscle toning or prescription of exercise or 
other hygienic measures. Lesions naturally vary in character 
and extent and present varying factors. From the very frequent 
vertebral rotation to the extended rigid area a great variety of 
structural perversions may be found. But it is the definite ad- 
justment of part to part, and of part to whole with a minimum 
of shock, and knowing when it is done, that characterizes the 
treatment. 

THE TWO FUNDAMENTALS. 

In our study of the osteopathic lesion, both clinically and 
experimentally, we are thoroughly convinced there are two funda- 
mentals that must be observed in order to secure a maximum of 
success in treatment: 

First, the bodily mechanism should be basically intact before 
further adjustment or correction is attempted. By this we mean 
the spinal column base (pelvis) should be structurally normal. 
Every mechanism should be "leveled up" before one can expect 
the superstructure to assume a relationship with a minimum of 



! 



GENERAL AND OSTEOPATHIC. 439 

friction or before one can hope to adjust the " boxes" with any 
degree of success; and it is not straining a point in the least (to 
the contrary, it is most practical) to say that with the human 
machine the relationship of sacrum and innominata (aside from 
the consideration of a possible " broken" plantar arch) must be 
" leveled up" or adjusted. This, then, gives us a foundation 
upon which to adjust the superimposed parts. Dr. Still has 
repeatedly urged us in our technique to commence at the bottom 
and seriatim "line up" the lesions above. Many lesions are 
compensatory or secondary to some lesion lower down in the 
structure, and will not yield or stay adjusted until the basic 
lesion is corrected; 

Second, a fundamental point in technique is specific adjust- 
ment. It is not enough to know where the lesion is, but we must 
know just how it is displaced. Most lesions are due to some 
form of rotation, and if we can analyze its characteristics it is 
then simply a matter of releasing the articular processes and ne- 
gotiating the return by the characteristics presented. 

We know this sounds easier than it really is. But, funda- 
mentally, a lesion in nearly every instance is a rotation, and if 
we would spend much more time on diagnosis and far less on hit 
or miss technique, with a little mechanical ingenuity, our thera- 
peutic efficiency would, at the very least, be doubled. The tech- 
nique should be a comparatively easy matter; it is the diagnosis 
that is difficult. There are many features that should be con- 
sidered. Aside from the mere mechanical problems there are 
the various local and general pathological conditions, strength 
and age of patient, etc. 

There is one other point, however, which should almost be 
dignified to a position as fundamental. It is a corollary of the 
above two fundamentals; it is to locate the "key" to a series of 
lesions, a curvature, a rigid area, or what is not infrequent, a 
distant lesion. To illustrate : A cervical lesion may be secondary 
to a dorsal twist, or rigid area to a lumbar or innominate devia- 
tion; in fact, there are innumerable gradations and combinations. 
Herein lies the really difficult work. 



440 PHYSIOLOGY ! 

In contrast to the above there are two things adjustment 
technique is not: 

First, treatment of " osteopathic centers." There is no 
such thing as specific treatment of centers (as we have empha- 
sized) , as some of us may be led to believe ; but there is most de- 
cidedly such a thing as specific treatment of osteopathic lesions, 
and this may be respective or irrespective of centers. A center 
is nothing more or less than a physiological grouping of neurones 
(as heretofore stated) for the special purpose of accomplishing 
some special act; for example, of contracting the walls of the 
stomach. It is not confined to a segment alone, but the co-ordina- 
tion includes two or three or more segments. Naturally a lesion 
within an area of say four or five segments will affect the innerva- 
tion of a viscus through vasomotor, viscero-motor or secretory 
fibers. The specific features of the lesion arise not so much with 
the matter of regional location as with the matter of maladjust- 
ment, and our ability to adjust with a minimum of exertion. 
" A nutritional center' 7 is simply the nucleus of the neuron; 

The second point of what "not to do" is muscle kneading 
and stretching. Not but what this has a place and is good sec- 
ondary treatment, but it must not be confused with the infinitely 
more essential and charateristic feature of specific adjustment. 
Many a refractory, contracted, or rigid area will yield in no other 
way than by adjusting some local or distant lesion. 

Lesions are very apt to occur in the anatomical weak points 
(where there is a "break in the continuity of structure"), and 
where habitual strain and stress is greatest, although not by any 
means confined to those areas, such as the innominata, fifth lum- 
bar, lower dorsal, upper dorsal, atlas, etc. Then in addition to 
the above, the relationship of a joint should be considered from 
both the static and functional viewpoints. An abnormal static 
position may locate the key to the lesion while the functional 
relationship will readily supply the key to executing the technique. 

To sum up : In our opinion, the study of practical technique 
should be more elemental. There has been too much confusing 
and clouding of the essentials by the various phases of general 



GENERAL AND OSTEOPATHIC. 441 

treatment, gymnastics, exercises, massage, stimulation, inhibition, 
osteopathic centers, and the like. Not that all these things are 
to be classed as " anatomy mussing" — time-killing stunts, but 
that they are utilized too often by those who really know better, 
as well as by the careless and inefficient, as osteopathic scape-goats. 
Consequently, a little of definitely applied mechanics with judi- 
cious attention to hygiene, diet, and corrective exercises, will 
approach Dr. Still's conception and success. 



CHAPTER XLVI. 
THE PRACTICAL APPLICATION. 

It would carry us beyond the confines and purposes of this 
article to outline the technique of the lesion. It has been our 
special scope to sketch the physiologic relation and importance 
of the same and its wide application in the etiologic field. We 
have emphasized that it is the etiologic concept of disease that 
characterizes the science of osteopathy. The art, the technique, 
is only a means to an end. However, of course, the means to 
an end is no small part of a school of the healing art, for upon the 
successful interpretation and application of a therapeutic measure 
does health or ill-health, or life or death, depend. 

After a student has become thoroughly imbued with the 
osteopathic concept, it is then a matter of study and observation 
and practice and experience before he can hope to become a fair 
technicist. He must possess or acquire a certain mechanical 
aptitude, a well-educated sense of touch, and a thorough appre- 
ciation that every case presents a distinct individuality. Although 
basic principles remain the same, the application is always differ- 
ent. There is no formula or rule of thumb to follow; this seems 
to be one of the most difficult things for the novice to thoroughly 
appreciate. Then in conjunction with the problems of technique 
arise those comprised in the fields of hygiene, sanitation, dietetics, 
surgery, toxicology, etc. 

On broad lines the field of practice includes prevention, cure,, 
and palliation. Physiologic functioning is the great desideratum,, 
based upon the fundamental biologic principle that function pre- 
cedes structure; this constitutes the great field of the future as 
exemplified in the growing child wherein growth, development, 
and plasticity of tissue are prominent features, and thereby nu- 

442 



GENERAL AND OSTEOPATHIC. 443 

trition, exercise of function, education, and integrity of structural 
relations are the means to the end. But upon the other hand the 
converse of this great principle, function precedes structure, is 
also true, and that is structure determines function, provided we 
remember that we are dealing with the individual whose struc- 
tures are either predetermined or in the adult have already at- 
tained completeness.* Herein, then, arises the immediate value 
of osteopathic adjustment and the significance of the principle to 
the physiologic unit, for normal structuralization is the basis of 
health from the standpoints of expediency and future normaliza- 
tion. This is the sound basis upon which technique rests, which 
of course must be tempered by good judgment as pathology, age 
of patient, environment, habits, etc., suggest. 

The physical make-up of an individual as shown by con- 
formation, configuration, relation. of segments, poise, and equi- 
librium is naturally influenced by the ever constant force of gravi- 
ty. There is always a constant and definite relationship between 
the structural lesion effects and the line of gravity. The inter- 
play between the osteopathic lesion and the gravity line is as dis- 
tinctive as between the pull of gravity and the different segments 
of the body. The relative proportions, or ratio, as exemplified 
by weight of head, torso, abdomen, pelvis and limbs, the mensural 
ratio as well, and the mobility, flexibility, and resiliency of tissue 
as shown by posture and poise, are all factors of the utmost practi- 
cal importance in this inter-relationship between the line of gravity 
and the osteopathic lesion. Compensation and adaptation upon 
the structural plane is but another way of expressing this relation- 
ship. 

Taking the vertebral lesion as a type it is not structural 
deviation alone that characterizes the same, but in addition there 
are other factors that determine the pathognomonic validity of 
the lesion, viz., restricted movement, contracted muscles, tender- 
ness, lessened vital response, variation in temperature, and dis- 
turbance of function.! These, or the majority of them, will be 
present whether the lesion involves a vertebra, rib, innominatum, 

*See McConnell, "Osteopathy in the Light of Evolution," A. O. A. Jour., May, 1913. 
fThe most important of these is restriction of movement, for the function of a joint is 
motion. 



444 PHYSIOLOGY : 

viscus, plantar arch, or any tissue or organ. With the vertebral 
lesion of a chronic nature the damaged articular ligament is the 
tissue that maintains the structural perversion; in the acute 
lesion it may rest with the muscles. From this arises a pathology 
due to nutritional changes in the nerve centers and from thence 
the neuron and its subsidiaries and collaterals initiate a more 
or less widespread involvement depending upon locality, severity, 
resistance, fatigue, and various contributing factors. 

The modus operandi for correction depends upon a measure 
that has for its purpose a release of the constraining tissues. Take 
the vertebral lesion: the application of a mechanical force that 
will precisely and definitely loosen the articular ligaments, whether 
it is by means of " exaggerate-the-lesion " principle, or approxi- 
mating the contiguous spinal segments so that all related tissues 
are more or less released, matters but little, provided the adjust- 
ment is specific and the resultant shock negligible. For the ex- 
tensive field of technique the student is referred to the various 
works and articles that treat of this work. There is one point 
in practical osteopathy that is too frequently neglected and that 
is the effect of reflex irritation upon the spinal lesion. The lesion 
may be of such disturbing character as to produce a severe visceral 
involvement, e. g., of the digestive tract, and in turn the reflex 
upon the vertebral muscles embracing the lesion is added to that 
of the vertebral lesion. It may be impossible to adjust the lesion 
until the organic disturbance somewhat subsides through pallia- 
tive and preliminary treatment of the lesion or dietetic measures 
that lessen the reflex effect, whence it will be comparatively easy 
to adjust the vertebrae. 

In conclusion we wish to add that above everything else 
technique is specific work. Every case is a law unto itself. There 
has always been too much of the " routine habit" in vogue instead 
of clean-cut therapy. Dr. Charles C. Teall has well said: "If 
every osteopathic physician would analyze each movement in a 
treatment — what is needed, why it is given, and what it will ac- 
complish, he would find that half his effort was unnecessary and 
it would make his work specific as well as compel a knowledge of 
conditions. " 






SECTION X 



RESEARCHES OF DR. BURNS 
AND DR. WHITING 



RESULTS OF OSTEOPATHIC RESEARCH. 

By Louisa Burns, M. S., D. O., D. Sc. O., 

Professor of Physiology, The Pacific College of Osteopathy. 



CHAPTER XL VII. 
THE BLOOD CELLS. 

In these studies of the development of the blood cells, and 
of the manner in which they are affected by abnormal condi- 
tions, the technique described by Emerson and used by his classes 
in the laboratories at Johns Hopkins, has been employed. 

The usual examinations made of the blood include: 1. The 
estimation of the hemoglobin; 2. The actual count of the ery- 
throcytes; 3. The actual count of the leucocytes; 4. The differ- 
ential count of the leucocytes. 

The hemoglobin is determined by means of Dare's hemo- 
globinometer. This is a very convenient instrument; its only 
handicap lies in the fact that it is not always exactly accurate. 
The Meischer modification of von FleischeFs hemoglobinometer 
is much more nearly exactly accurate, but it is clumsy to use and 
a great deal of time is needed both for the testing of the blood 
and for cleaning the apparatus afterwards. 

In the studies here reported the von Fleischel instrument 
has been employed to check up the Dare's hemoglobinometer, 
and the Dare's then used for the determination of the hemoglobin 
in most cases. 

The actual counting of the red and white cells was done by 
means of the Thoma-Zeiss apparatus. The counting chamber 
with Turck ruling was found most convenient. The blood was 

447 



448 physiology: 

diluted two hundred times with Toisson's fluid, both for the 
erythrocytes and the leucocytes. After mixing the blood by 
shaking for two minutes and discarding the first four drops of 
the solution, the counting chamber was filled in such a manner 
as to prevent any bubbles of air being found under the cover. 
The drop was large enough to flow into the moat slightly, but 
not to flow over the square of glass which supports the cover 
glass. The pressure made upon the cover glass was usually 
sufficient to cause the appearance of the rainbow colors. Some- 
times the glass was not sufficiently perfectly ground to permit 
this appearance. 

The erythrocytes were counted in fifty of the small squares 
on the counting chamber and the leucocytes over the entire field, 
that is, of thirty-six hundred small squares. The counting cham- 
ber was then washed and dried, and a second drop prepared and 
counted in the same manner. A third drop was prepared in the 
same manner, but no red cells were counted, and only the leucocytes 
in eight hundred small squares were counted. This makes a 
count of the erythrocytes in one hundred small squares, includ- 
ing two drops of solution; the leucocytes in eight thousand small 
squares, including three drops of the solution. Since each small 
square includes one four-thousandth part of a cubic millimeter, 
and since the blood has been diluted two hundred times, it is 
evident that the number of small squares found in one hundred 
small squares, multiplied by eight thousand, must give the number 
of erythrocytes in each cubic millimeter of blood. In like manner 
the number of leucocytes found in eight thousand small squares, 
multiplied by one hundred, must give the actual number of leu- 
cocytes in each cubic millimeter of blood. 

The differential count of the leucocytes was made for the 
purpose of determining the relative numbers of the different 
classes of leucocytes in the blood. This determination cannot 
be made by the use of the counting chamber, partly because the 
chamber is too deep to permit a sufficiently high power of the 
microscope to be used, and partly because the rarity of certain 




Lymphocytes 



Eosinophils 



Basophiles 



Neutrophils 



Erythrocytes 



Plate XXXIII.— Leucocytes. 



GENERAL AND OSTEOPATHIC. 449 

forms would necessitate the counting of an enormous number 
of chambers in order to secure anything like accurate results. 

For the differential count, thin smears of the blood were 
made upon ordinary cover glasses. These were dried in the 
air and stained. Wright's stain, eosinate of methylene blue, 
was used in all cases included in this report. This was made with 
slightly varying technique, but the essential principle is the same — 
the precipitate from a mixture of watery solutions of eosin and 
of methylene blue was dissolved in methyl alcohol. The dried 
blood smears were covered with this stain and left for three to 
six minutes, according to the temperature and humidity of the 
air. Water was then added, a drop at a time, until the stain 
appeared quite thin. It was then left two to six minutes, then 
washed very thoroughly in water and mounted with water upon 
a slide and examined. 

By this method the nuclei are all pale blue or purple; the 
lymphocytes have blue protoplasm and are hyaline, the neutro- 
philes are light pink or lavender, with small granules; the eosino- 
philes are brilliant eosin color with very large granules; the baso- 
phils are deep indigo, with very large granules. 

For ordinary work a differential count based upon the naming 
of five hundred white cells is fairly exact. In most of the cases 
included in this report one thousand or two thousand white cells 
were counted. 

Having determined in this manner the percentages of the 
various classes of white cells, it is necessary only to multiply the 
actual numbers of leucocytes per cubic millimeter by these figures 
in order to determine the actual number of each class of leucocytes 
present in each cubic millimeter of blood. 

The cells found in normal adult human blood include the 
following classes : 

A. Erythrocytes 

B. Leucocytes. 

1. Hyaline leucocytes 

a. Small lymphocytes 

b. Large lymphocytes 



450 physiology: 

2. Granular leucocytes 

a. Monouclear neutrophiles 

b. Polymorphonuclear neutrophiles 

c. Eosinophiles 

d. Basophiles 

C. Platelets are often included as cells, but their nature 
has not yet been determined. 

The erythrocytes number four and one-half to five million 
to each cubic millimeter of blood. These figures are lower than 
the counts made in this locality indicate. Five to five and one- 
half million is more nearly an average count of the blood of normal 
men and women made in this laboratory. (The Pacific College 
of Osteopathy, Los Angeles, California.) It may be that the 
dry atmosphere of this climate is responsible for a certain amount 
of concentration of the blood. 

Each erythrocyte is a thin, saucer-shaped body with no 
nucleus, and composed almost entirely of hemoglobin lying in the 
interstices of a protoplasmic stroma. The relative amount of 
hemoglobin carried by each erythrocyte is represented by a frac- 
tion called the color index. The color index is the fraction ob- 
tained by dividing the hemoglobin percentage by the erythrocyte 
percentage. 

The relative amount of hemoglobin carried by any given 
mass of erythrocyte protoplasm is called the volume index. This 
is the fraction obtained by dividing the hemoglobin percentage 
by the volume percentage of the erythrocytes. This is secured 
by the use of a hemocrit. 

Erythrocytes are constantly being formed by the hemato- 
poietic cells in the red bone marrow, especially in the flat bones, 
such as the ribs. The life of an erythrocyte is known to be short, 
perhaps a matter of a few days, perhaps a few weeks. The amount 
of urinary and bile pigments formed from disintegrated hemo- 
globin each day gives some idea of the enormous destruction of 
erythrocytes occurring constantly in the body. 

It seems that some erythrocytes are, or may be, formed by 
budding. These may never be nucleated. It appears certain 



GENERAL AND OSTEOPATHIC. 451 

that they are also formed by means of the ordinary processes of 
karyokinesis, and that the nuclei are extruded before they go 
into the general circulation, under normal conditions. The 
number formed during any given time is only to be very vaguely 
determined; certainly many thousands of new erythrocytes are 
formed each minute of the day and the night. 

Leucocytes are the colorless cells of the blood. They are 
always nucleated, include several different forms, and appear 
to have functions as variable as their structure. There are from 
five to ten thousand leucocytes in normal adult human blood 
in this climate. 

The hyaline leucocytes are characterized by the ( absence 
of granules in their protoplams. The protoplasm is scanty in 
amount, stains with basic stains (methylene blue, with Wright's 
stain), and surrounds the nucleus thinly. The nuclei of the hya- 
line cells are round or only slightly indented in a kidney shape. 
The nuclei may be eccentrically placed. Under slightly abnormal 
conditions and in the lower mammals the hyaline cells may con- 
tain a few basic granules. The small lymphocytes and the large 
lymphocytes differ chiefly in size; the large lymphoctyes carry 
a relatively greater amount of protoplasm. 

The lymphocytes originate in the lymph nodes, the red bone 
marrow, the spleen, the lymphoid tissue generally. The large 
lymphocytes make up four to ten per cent of the white blood 
cells, the small lymphocytes from fifteen to twenty-five per cent. 

The granular leucocytes are characterized by the presence 
of granules of various sizes and staining properties lying in the 
protoplasm, apparently making up the mass of the protoplasm 
in some cases. 

Mononuclear neutrophiles carry the smallest granules. These 
take neutral stains; with Wright's stain they are either light 
pink or lavender. The nuclei are round or slightly lobed or 
notched, and are almost centrally placed. The cells called transi- 
tional are frequently included with this group. Two to four 
per cent of the white cells may be mononuclear neutrophiles. 

Polymorphonuclear neutrophiles resemble the mononuclear 



452 PHYSIOLOGY : 

forms slightly. In these the granules are slightly larger, and 
they take a deeper pink color with Wright's stain. The nuclei 
are of many sizes and shapes. In many cases it is easy to see that 
the different lobes of the nucleus are united by slender threads 
of nuclear substance, but often the nucleus appears to be really 
multiple. In normal blood the polymorphonuclear neutrophiles 
have nuclei which look more like a ribbon folded upon itself in a 
rather complex manner than like a string of sausages. It is sup- 
posed that the polymorphonuclear forms are developed from the 
mononuclear forms, and that the greater the number of nuclei, 
or of distinct lobes in the single complex nucleus, the older is the 
leucocyte. These cells originate in the red bone marrow, chiefly, 
though some appear to be derived from the spleen and from the 
hemolymph glands. They make up two-thirds to three-fourths 
of the white cells of normal adult human blood. 

Eosinophiles are characterized by the intensely vivid eosin 
color which they take with Wright's stain. The granules are 
very large, and take the acid stains with avidity. The nuclei 
are one or more and are rounded in outlines. They make up 
about two to five per cent of the white blood cells in human blood 
and originate chiefly in the red bone marrow. 

Basophiles also have one or more rounded nuclei, and have 
their protoplasm almost filled with very large granules. These 
granules stain a deep and vivid indigo blue with Wright's stain. 
They are often lacking in normal human blood, but may take 
up one per cent of the white cells. They originiate in the red 
bone marrow. 

Under abnormal conditions other forms of white cells may 
be found in human blood. 

Myelocytes are characterized by their large size, and by their 
large, rounded, and very eccentric nuclei. The nucleus occupies 
about one-third of the periphery of the cell. These are found 
in normal bone marrow, but only under pathological conditions 
do they appear in recognizable numbers in the general circulation. 
Rarely, one or two might be found in an ordinary smear of normal 
blood. 




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GENERAL AND OSTEOPATHIC. 453 

Amphophiles carry granules which have affinities for either 
acid or basic stains. With a pure eosin stain they appear eosino- 
philic, with methylene blue they appear basophilic. With Wright's 
stain they show both red and blue granules. These cells are 
normal to the blood of the lower mammals and to human blood 
during early fcetal life. Abnormally they may be found in adult 
human blood. 

Turck's irritation forms are usually neutrophilic. They 
are roughly triangular, and the large round nucleus occupies one 
corner of the cell. It is naked for about half its extent. These 
cells are normal to lower vertebrates; we have not found them 
normally present in the blood of any mammal examined. Under 
very severe nutritional disturbances they may be found in human 
blood. 

Transitional forms occupy the gradation stages between the 
large lymphocytes and the mononuclear neutrophiles. They 
have hyaline, basic protoplasm, containing a variable number 
of very small neutrophilic granules. They are rarely found in 
normal human blood, and are included with the mononuclear 
neutrophiles in counting. 

Bony Lesion and Blood Formation. — A report regarding 
the relationship between lesions of the ribs and vertebrae upon 
the formation of the blood cells was given at the meeting of the 
American Osteopathic Association at Minneapolis in 1909. 

Nerves of the Red Bone Marrow. — The demonstration 
of the terminations of the nerves entering the red bone marrow 
is somewhat difficult, because of the bony spicules present. A 
modified methylene blue method gave best results. 

The marrow was taken from the bone as soon after 4 anesthesia 
was complete as possible. Pieces not more than ten millimeters 
were placed in a solution of 1-2% methylene blue in normal 
salt solution, preferably at blood temperature. After about ten 
minutes they became deep blue. Then they were washed lightly 
and quickly in water, then in a watery solution of picric acid, 
again in water, then the pieces were lightly teased apart in 
glycerine. By this technique very pretty nerve endings can be 
seen. 



454 PHYSIOLOGY : 

Many nerve fibers break up into fibrillar among the marrow 
cells. We were not able to find any specific endings, other than 
these, nor were we able to find that they had any direct relation 
to the marrow cells. Other nerves terminate upon the walls 
of the blood vessels. Certain experiments indicate that these 
are dilator nerves. 

After the preliminary anesthetic, usually ether, the thorax 
was opened and the ends of the ribs cut. The nerves were 
dissected back from the nutrient foramina for an inch or 
more, then cut. The vessels were kept separate from the 
nerves. The rate of blood flow from the cut ends of the ribs 
was noted, then the peripheral end of the cut nerve was stimulated 
— usually by a weak alternating current of electricity, but some- 
times by pinching or pricking the nerve trunk. The blood flowing 
from the cut end of the rib increased and the blood became bright- 
er in color. Similar tests were made upon the red bone marrow 
of the humerus of the cat and upon the skulls of both cats and 
dogs. The results were the same in all cases. 

Tests were made upon human subjects in order to determine 
the relationship between the rib movements and the formation 
of the blood cells. For this purpose twenty-seven persons, suffer- 
ing from no recognizable disease, but who were below par in physi- 
cal vigor, were chosen. In all of these cases the hemoglobin was 
low; the erythrocyte count normal or higher than the average; 
the color index was low; the leucocyte counts showed slight 
variations from the normal, none constant except the relative 
excess of lymphocytes. 

In every person thus examined the thorax was more rigid 
than normal and the respiratory movements were remarkably 
slight. In a few the respiratory excursions in quiet respiration 
were so slight that they could not be measured by the ordinary 
steel tape. The average expansion in quiet respiration was two 
millimeters; in forced respiration, fifteen millimeters. 

Ten of the subjects were dropped from the tests for various 
reasons; seventeen were able to carry on the tests for seven weeks. 



GENERAL AND OSTEOPATHIC. 455 

These persons were directed to continue in their usual habits 
of eating and living, except for the increasing mobility of the 
thorax. Three times each week treatments were given, for the 
correction of specific rib lesions when these were present, and for 
raising the ribs and increasing the mobility of the thorax in all. 
Breathing exercises adapted to each person's condition were out- 
lined, and these also were planned for raising the ribs, increasing 
the mobility of the thorax, and thus facilitating the efficiency 
of the circulation and nervous control of the ribs. The obedience 
with which these directions were followed was evident in the fact 
that the expansion in quiet breathing increased from one to five 
millimeters, while the expansion in forced respiration increased 
slightly. 

The blood was examined for each person at rather irregular 
intervals, depending upon circumstances. At the end of seven 
weeks the blood was examined for each person, and the records 
compared. The following changes were found to have occurred, 
evidently as the result of the treatment as outlined: 

The hemoglobin was increased in every person, the average 
increase being 19% by Dare's hemoglobinometer; 

The erythrocytes approached the normal in each case in 
which the normal count was not present at the beginning of the 
tests. There was an average loss of 5% in actual numbers; this 
was associated with increased regularity and size of the cells them- 
selves ; 

The color index was raised in all but one case, the average 
rise being .185; 

Microcytes were present in five cases at the beginning of the 
experiments. None were found in the last examination; 

Poikilocytes were present in six cases at the beginning of the 
tests. A few were still present in three cases at the last examina- 
tion ; 

In two cases the leucocytes were slightly diminished; in 
six they were slightly increased, in the other cases no changes 
were apparent. The white cells either remained normal from the 
beginning or approached normal during the tests. This was 



456 PHYSIOLOGY : 

true both of the percentages of the various classes and also of the 
actual numbers of each class present in each cubic millimeter of 
blood. 

From these tests and from a study of clinic patients during 
their improvement, it appears that the character of the blood may 
be seriously modified by a lack of mobility of the ribs. The 
location of those bony lesions which affect the digestion and 
absorption of food, or the elimination of the bodily wastes, is 
evident. In addition, the place of the thoracic rigidity in inter- 
fering with the normal circulation and innervation of the red 
bone marrow must not be forgotten. 

The habit of pronounced abdominal breathing, the wearing 
of clothing which impedes the movements of the ribs, and a sedent- 
ary life are important factors in causing these slight forms of 
anemia. An interesting point in development may be noted: 
One effect of our civilization is an endeavor to prevent manifesta- 
tions of emotional storms. Thus civilized man does not yawn, 
laugh, or weep extravagantly, or display much of any feeling by 
means of the breath variations. Children and certain savage 
races are wiser; the respiratory movements thus made extrava- 
gant, increase also the circulation through the red bone marrow 
and the formation of blood cells. Perhaps no one would advocate 
a return to savagery for the sake of securing red blood cells, but 
certainly a return to the more mobile thorax and the greater 
chest expansion in quiet respiration is worth while for the sake of 
redder and better blood. 

The Blood of Neurasthenics. — A report was made upon 
this subject at the meeting of the California State Osteopathic 
Association held in San Diego in May, 1909. The blood of thirty- 
three neurasthenic patients, without recognizable organic disease, 
was examined one or several times. The results are as follows: — 

Specific Gravity Decreased 

Coagulation Time Increased 

Hemoglobin 61 . 8%of the normal 

Erythrocytes 104. 4% of the normal 

Color Index 61 




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GENERAL AND OSTEOPATHIC. 457 

Leucocytes 14593 per cubic millimeter 

Large Lymphocytes 711 per cubic millimeter 

Small Lymphocytes . . . 2743 per cubic millimeter 

Mononuclear Neutrophiles 159 per cubic millimeter 

Polymorphonuclear Neutrophiles.. 10287 per cubic millimeter 

Eosinophils 496 per cubic millimteer 

Basophiles 197 per cubic millimeter 

Amphophiles, present in 9 cases. 
Neutrophilic Myelocytes, present in 11 cases. 
Microcytes, present in 12 cases. 
Poikilocytes, present in 21 cases. 
Microcytes, present in 1 case. 
Normoblasts, present in 3 cases. 

Examinations of the blood of fifty other patients with neuras- 
thenic symptoms verifies the results given in this report. 

The blood of neurasthenic patients shows the following 
-characteristics: Low hemoglobin, high or normal erythrocyte 
•count, low color index, slightly increased leucocyte count, eosino- 
philia, and a tendency to the appearance of the immature or 
atavistic forms. In a few cases the blood of patients supposed 
~to be neurasthenic has varied recognizably from this picture. 
In all such cases some organic lesion has become manifest upon 
further investigation. 

A report upon "Some Atavistic Characters of Abnormal 
Blood" was made in 1912. A summary was given before the 
meeting of the American Osteopathic Association in Detroit, 
and the paper was published in the Journal of the Association for 
September, 1912. This report was based upon a study of five 
hundred examinations of human blood and of the blood of thirty 
animals. Since that time the blood of other animals and of human 
b>eings under various abnormal conditions has been examined. 
These later tests add to the number of facts and to the details 
of the relationships, but do not, so fail to verify the conclusions 
given in that report. 

Hemoglobin. — The hemoglobin percentage (Dare) varies 
rather irregularly among different animals. In general, the 
amount of hemoglobin increases from the lower vertebrates to 
the higher, from the young of all animals to the old, and is lower 
under abnormal conditions. There are certain exceptions to 



458 physiology: 

these statements, as the percentage of hemoglobin is very high 
in diabetes, both insipidus and mellitus, due to the concentra- 
tion of the blood. Dietetic variations modify the hemoglobin 
also. 

Color Index. — The color index also varies irregularly. In 
non-mammals the color index is high, because the erythrocytes 
are very large. This is the case also in pernicious anemia. In 
small animals (for example, mice), the color index is usually low 
because the erythrocytes are small. The color index rises from 
foetal life to youth and from youth to old age. It is usually lowest 
in abnormal conditions, both among animals and human beings. 

Volume Index. — The volume index refers to the relative 
amount of hemoglobin carried by a given amount of erythrocyte 
cytoplasm. The volume index is thus indicative more exactly 
of the evolution of the hemoglobin. It increases invariably from 
the lower to the higher vertebrates, from foetal to young blood, 
and from young blood to that of old age. It is higher under 
normal than under abnormal conditions, including diabetes and 
pernicious anemia. 

Erythrocytes. — Below mammals the erythrocytes are oval, 
large, nucleated, and rather irregular in shape and size. They 
are usually fairly constant in staining, so far as the stroma is 
concerned, but vary in the density, due to hemoglobin. The 
stroma is very distinct and often includes granules of varying 
affinities. 

Among mammals the lower forms generally show the more 
distinct stroma, the lower volume index, the greater irregularity 
of size, shape, and staining, and the greater tendency to disinte- 
gration during the manipulations necessary to counting and 
staining. 

The ontogenetic development presents a similar series of 
events. From foetal blood to that of youth, from youth to adult 
life, and, under normal conditions, to old age, the erythrocytes 
contain a relatively greater amount of hemoglobin, are more 
regular in size, shape and staining, and retain their outlines more 



GENERAL AND OSTEOPATHIC. 459 

constantly during the technique of the tests made in the prepara- 
tion of this report. 

The macroblast of pernicious anemia has long been considered 
a " harking back" to the invertebrate type of erythrocyte. The 
low color index in chlorosis and in secondary anemias, the low 
volume index in most diseases, the presence of poikilocytes, and 
the speedy disintegration of the erythrocytes in the making of 
smears and in the counting pipettes and chamber are character- 
istic alike of abnormal blood of human beings and animals, of the 
3^ounger children and animals, and of the lower forms of mammal- 
ian blood. 

Leucocytes. — Generally speaking, the leucocyte varies under 
both physiological and pathological conditions more rapidly in 
the lower mammals than in the higher; in the young than in the 
old, and in the feeble than in those of robust physique. It is 
thus evident that fluctuations in the leucocyte count are of less 
significance in the blood examinations of children and of feeble 
adults than in the examinations of the blood of robust adults. 

Lymphocytes. — In all of the blood examined, human or 
animal, young or old, normal or diseased in any way, the hyaline 
cells are basophilic. The giant mononuclear hyaline cells are 
not normally found in the blood of any mammal examined. They 
are normal to birds, reptiles, and amphibia, and are found under 
certain very severe nutritional disturbances (pernicious anemia, 
spleno-medullary leukemia, just before death in a meningitis 
following a long septicaemia, etc.). 

The large and small lymphocytes decrease in percentages 
from the lower to the higher mammals, from the foetal to the 
young, and from youth to old age, and under most conditions 
associated with diminished nutrition. 

Neutrophiles. — Neutrophiles are rarely present below mam- 
mals, and are so unstable that they appear to be more rare than 
they really are. They are almost or quite invariably mononu- 
clear in non-mammalian blood. 

Among . mammals the percentages of neutrophiles increase 
from the lower to the higher forms of life, from fcetal to youthful 



460 PHYSIOLOGY : 

blood, and from youth to old age. Under abnormal conditions 
these cells vary in both directions, being diminished relatively 
in mal-nutrition and increased in the presence of inflammatory 
conditions. 

The nuclei of neutrophiles present interesting variations. 
The mononuclear type is, phylogenetically, ontogenetically, and 
perhaps, individually, the youngest form. The fewer the number 
of nuclei, the younger is the cell type. Blood containing larger 
numbers of neutrophiles having one or two nuclei is thus to be 
considered more immature than blood containing great numbers 
of neutrophiles with four to six or more nuclei. 

Eosinophils. — Eosinophiles vary irregularly in phylo- 
genetic and ontogenetic development. Among lower mammals 
the granules are often extremely large and are sometimes rod- 
shaped, as in the horse. They have generally larger and rounder 
nuclei in the lower forms of mammals and in immature blood, 
but this is not constantly true. Under abnormal conditions 
they appear to be increased in the presence of animal invasions 
practically invariably, and after certain bacterial infections. In 
certain functional variations, both physiological and pathological 
they may be increased. Their absolute numbers are decreased 
in tuberculosis and under certain other less well recognized con- 
ditions. 

Basophiles. — Basophiles are found in great numbers in 
most non-mammalian blood. They are more often mononu- 
clear among the lower forms, both of mammalian and non-mam- 
malian blood. They are often absent in normal adult human 
blood, and may or may not be increased under pathological con- 
ditions. Basophilic granules are often present in the hyaline 
cells of the lower mammals and non-mammals, but are rarely 
found in normal adult human blood. They are sometimes found 
in human fcetal or placental blood, in children's blood, and in 
the blood of adults suffering from severe mal-nutrition. 

Amphophiles. — Amphophiles are found in the blood of 
non-mammals and of the lower mammals. The most beautiful 
amphophiles found in this laboratory (Laboratory of Physiology, 




Plate XXX VI. —Showing the arterial connections between the brain and cord and the 
cervical autonomics extending to the arteries of the head and neck. Note the close structural 
relations of bony framework with the blood and nerve supply. A, circle of Willis; B, posterior 
cerebral; C, internal carotid; 1, basilar arterv; 2, vertebral arteries; 3, anterior spinal arteries; 
4, symphathetic chain; 5, vertebral artery and vein in transverse process; 6, brachial plexus, 
7, carotid artery; 8, first intercostal artery; 9, subclavian artery; 10, subclavian vein: 11. 
superior vena cava; 12, vena azygos major. 



GENERAL AND OSTEOPATHIC. 461 

The Pacific College of Osteopathy) have been those from the 
blood of a Belgian hare which was about half grown. They were 
not found in appreciable numbers in normal dogs or cats nor in 
the blood of normal people. In severe secondary anemia, after 
profound hemorrhages, in the leukemias, and under a number 
of varying cachexias, amphophiles were found in adult human 
blood. 

Since these reports were first published many other blood 
examinations have been made of normal and abnormal persons 
and of normal and abnormal animals, in both cases of many ages. 
These later tests verify the findings first reported in every case. 



CHAPTER XL VIII 
REFLEX ACTIONS. 

The manner in which the body as a whole reacts to the changes 
in the environment of any of its parts or the variations in the 
conditions of any of its parts, depends largely upon the existence 
of a complex series of nervous activities which are called reflex 
actions. 

A reflex action is any variation of physiological activity which 
results from a motor-nerve impulse initiated by a sensory impulse, 
without the intervention of consciousness. 

It is at once evident that a very large proportion of the phe- 
nomena of the daily life of human beings and of many animals 
is based upon reflex actions; it is also evident that the greater the 
possible number of reflex actions and the greater the flexibility of 
the adjustments secured by these reflexes, the greater is the 
efficiency of the organism. 

The efficiency of reflex actions depends chiefly upon the 
structural and physiological relationships of neurones arranged 
in groups within the central nervous system. Such groups of 
neurones arranged in such a manner as to control the activy of 
any organ or group of organs, or for the performance of any spe- 
cific function, are called nerve centers. 

Nerve centers may be considered as individual groups of 
neurones, for purposes of discussion, but it must be remembered 
that the same phenomena might be produced by the varying 
activities of groups of cells acting under varying circumstances 
that would be produced by entirely different cell groups. It is 
at present impossible to determine the actual extent of any of 
the more complex nerve centers; that is to say, the physiology 
of the nerve centers has been studied more exactly than has their 
morphology or their histology. 

462 



GENERAL AND OSTEOPATHIC. 463 

The typical nerve center is, in a sense, the keystone of a re- 
ilex arc. It receives the axons of sensory neurons, usually both 
of the first and second orders, and sometimes of higher orders; 
it includes association cells, and it sends the impulses co-ordinated 
by these varied activities to the active tissues of the body by way 
of motor neurons of the first, second, or higher orders. In addi- 
tion to these neurons, essential to nervous activity of more than 
the simplest type, each neuron receives axons from the nerve 
centers of related function and sends axons to them. Thus the 
structural relationships of the nerve centers are complex and 
varied, and the functional relationships are such as enable them 
to perform the most complex, varied, and efficient actions. In the 
case of the nerve centers of the spinal cord, it is known that the 
descending spinal tracts carry nerve < impulses from may higher 
centers which may increase or decrease the activities of the cen- 
ters themselves or of the neurons composing them. 

The activity of any nerve center may be modified by any of 
the following factors: — 

1. The structural relationships of its neurons. Not only 
are the functions of normal nerve centers dependent upon the 
existence of cells and axons for the co-ordination of the nerve 
impulses, and nerve fibers for the transmission of these, but under 
abnormal conditions the structural relationships may become 
disturbed to such a degree as to prevent normal activity. The 
failure of a normal structural development of the nerve centers 
underlies the physiological and mental defects of idiot, imbecile, 
and feeble-minded children. There is some reason to believe 

' that the functional nervous weakness in many hysterical and 
neurasthenic patients depends upon a lack of the proper structural 
development of the neurons of the central nervous system. 

2. The physiological condition of the neurons composing 
the center. Neurons which are fatigued do not react in the same 
manner as do rested neurons. Neurons which are well fed with 
clean blood, flowing freely under normal pressure, derived from 
well-digested, nutritious food, behave in such a manner as to 
adapt the body to its environment most efficiently; but a lack 



464 PHYSIOLOGY : 

of nutrition, of oxygen, or of the internal secretions, or the presence 
of any of a long list of poisons of intrinsic or extrinsic origin, or 
too low or too high a pressure of the blood, or any other abnor- 
mality in the nutrition of the neurons, prevents the most efficient 
activity. Neurons which are frequently stimulated react more 
speedily and usually more efficiently than do those which are 
rarely stimulated. Under certain circumstances the increased 
or decreased activity of one center may render centers of related 
function more easily stimulated or more resistent to stimulation. 

3. The character of the nervous stimuli reaching them. Thus 
the spinal centers may be stimulated by sensory impulses from the 
same or adjacent spinal segments; by impulses from centers 
of related function; by impulses descending from the centers of 
the medulla, pons, cerebellum, mid-brain, basal ganglia, and 
cerebral cortex. Volitional impulses may affect the activities 
of certain spinal centers also. The activities of the higher centers 
are modified in practically the same manner as the spinal centers, 
with such modifications as depend upon their structural relation- 
ships. The nerve impulses may either increase or inhibit the 
activity of any center. 

Bony Lesions. — The anatomy, histology, and physiology 
of the spinal cord and the sensory ganglia indicate that the most 
important factor in the relationship between the slight mal-posi- 
tions of vertebrae, ribs, and other bones is found in the phenomena 
of reflex action. These slight mal-positions are called "bony 
lesions. " 

Bony lesions may modify the activities of the spinal centers 
by modifying the character of the sensory impulses. This effect 
is probably secured by impulses passing over several varying 
pathways. Perhaps one of the most important effects is pro- 
duced by the irritation of the sensory nerve endings upon the 
articular surfaces of the bones whose relationships are disturbed. 
A number of experiments have been performed by several ob- 
servers in different laboratories in the effort to explain the effects 
produced by bony lesions. The work done in the laboratory of 
physiology of The Pacific College is here given in summary. 



GENERAL AND OSTEOPATHIC. 465 

The experiments were performed upon animals and human 
beings. For the most part, the tests were limited to the immediate 
effects of bony lesions. Of animals, cats, dogs, guinea pigs, 
white rats, and rabbits were employed. Ether was the usual 
anesthetic and anesthesia was complete before any mutilating or 
painful tests were made. 

After the anesthesia was complete, the viscera to be studied 
were exposed to view. Acids, hot glass tubing, prickings, chem- 
ical substances, and light electric currents from a DuBois Ray- 
mond coil were used for stimulation. The electric current was 
most useful, and was usually barely perceptible to the touch. 
The length of the tests was limited to the time during which life 
could exist under anesthesia and during the necessary mutilations. 
No animal was ever permitted to suffer, or to regain consciousness 
after the anesthetic was begun. 

Effects of Spinal Stimulation. — In one series of tests the 
effects produced upon viscera, blood vessels, glands, and the 
skeletal muscles by stimulation of the tissues near the spinal 
column were studied. After anesthesia the viscera were exposed 
to view, and the tissues to be manipulated were brought into a 
convenient position. The tests were repeated upon different 
animals, and in regard to the larger viscera of the cranial, thoracic, 
abdominal, and pelvic cavities. The changes were noticed by 
several observers, working independently; these were often stu- 
dents who did not know what reaction was expected, but were 
merely told to report whatever changes they noticed. Secretions 
were collected and analyzed in a few instances. The results of 
these tests are given in general at this time, and the results of 
localized tests are given in a later paragraph. 

Stimulation of the skin may be followed by no recognizable 
effects. Sometimes slight variations in the circulation of the 
blood, the secretion of large glands, peristalsis, or the tone of the 
deeper muscles could be recognized. Both in human beings 
and in animals irritation of the skin over the back of the neck 
produced dilatation of the pupils. 



466 PHYSIOLOGY : 

Stimulation of the superficial spinal muscles produced about 
the same effects. 

Stimulation of the deeper spinal muscles was followed by 
increased tone of the skeletal and visceral muscles, constriction 
of the arteries, and in some cases by increased secretions. 

These effects were more marked when the stimulation was 
applied to the muscles near the vertebrae than when the muscles 
of the same layer but further from the spinal column were stimu- 
lated. 

Stimulation of the articular surfaces of the vertebras, ribs, 
and the scapula, clavicle, mandible, and skull was followed by 
still more marked effects. Peristalsis was increased, blood pres- 
sure noticeably raised, partly by the increased tone of the vascular 
walls. The secretions were increased in quantity, and the skeletal 
muscles innervated from the same segment were strongly con- 
tracted. In the case of the salivary glands the amylolytic 
power was increased by irritation of the articular surfaces of the 
mandible. In the case of the vertebral articular surfaces the 
effects produced were broadly segmental. 

Effects of Visceral Stimulation. — In another series of 
experiments the effects produced by visceral irritation upon the 
spinal muscles were studied. In this series the stimulation was 
applied to the viscera and the location of the reflex muscular 
contractions thus produced was noted. The deeper spinal muscles 
and the intercostal muscles innervated from the same segment 
which sent sensory nerves to the viscera stimulated were invar- 
iably contracted. Muscles innervated from neighboring segments, 
and the larger and more superficial muscles of these segments 
were usually contracted. The muscles of the limbs were rarely 
contracted. The area of reflex muscular contraction increased 
when the stimulation was long continued. 

The reflex muscular contractions thus produced should be 
considered an efficient cause of further irritation to the spinal 
centers. The reflex paths apparently include the same spinal 
centers and the same nerve trunks, for the most part, whether 
the sensory impulses from the viscera affect the spinal muscles, 



i 



GENERAL AND OSTEOPATHIC. 467 

or the irritation from the vertebral or costal articular surfaces 
affects the condition of the viscera or the tone of the blood vessels. 

From this series of tests, including several hundreds of ex- 
periments, the following conclusions concerning the nerve centers 
and the effects of bony lesions have been based: 

Bony lesions are slight mal-positions of the bones, usually 
the vertebrae or ribs, which are less pronounced than dislocations, 
by means of which the articular surfaces are thrown into a state 
of more or less strenuous tension. This stress upon the articular 
surfaces is a constant source of irritation to the sensory nerve 
endings therein, and is thus a cause of abnormal nerve impulse 
reaching the nerve centers of that particular segment of the 
cord. The ultimate effects thus produced may be variable — 
since too great activity of any neuron or neuron system may lessen 
or increase its liminal value, or may even result in a sort of func- 
tional paralysis. Some disturbance of the function of the centers 
of that segment of the cord, and ultimately of neighboring segments 
also, is probably invariable. 

Disturbance of the activity of any of the centers of the cord 
means a disturbance of the structures innervated from those 
centers. The effects produced upon the body itself thus depend 
in part upon the location of the lesions and in part upon the nature 
of structures innervated from that part of the cord. When the 
centers controlling the circulation are affected, then the nutri- 
tion of the nerve centers is apt to be affected by this disturbed 
circulation. When the centers controlling the digestion or the 
absorption of food are affected the nerve centers also are poorly 
nourished. When the circulation through the flat bones, espec- 
ially the ribs, is affected, then the quality of the blood becomes 
abnormal, and the nerve centers are thereby affected. So, what- 
ever the effects produced upon the body metabolism, there is 
usually also an indirect effect upon the nerve centers as well as 
the more direct effects of the modified stream of sensory impulses 
from the strained articular surfaces. 

The cells of the anterior horns of the spinal cord are arranged 
in two groups — a mesial cell group, composed of rather small 



468 PHYSIOLOGY : 

cells with correspondingly fine axons, and a lateral cell group , 
composed of larger cells with coarser axons. 

The cells of the mesial group send their axons into the smaller 
muscles of the deeper layers of the back and neck. It is their 
especial function to maintain the erect position and to keep the 
vertebral relationships normal. These cells are very intimately 
associated with the sensory neurons, visceral and somatic, and 
with the cells of the neighboring segments of the cord. They 
receive descending impulses from the cerebellum, pons, medulla, 
mid-brain, and ganglional centers in a noticeable degree, but 
only to a slight extent are controlled by impulses from the pre- 
central areas of the cortex. 

The cells of the lateral group of the anterior horn are found 
best developed in the cervical and lumbar enlargements. They 
send their axons to the large muscles of the back and shoulders 
and hips, and of the arms and legs. They are not especially in- 
timately associated with the sensory neurons of the same segments 
of the cord, though there is a certain amount of connection in func- 
tion. These cells receive impulses from the cerebellum and 
from the precentral areas of the cortex to a great degree, but 
only rather slightly from the medullary and pontine centers. 
Visceral or other sensory nerve impulses rarely produce reflex 
muscular contractions of the limb muscles to any great extent. 

With the quantitative exceptions just noted, the cells of 
these groups of the anterior horns are controlled by means of 
impulses carried by about the same pathways. 

1. Axons and collaterals from the sensory neurons of the 
first or higher orders form synapses with these cells. By this 
means the simple and the more complex reflex actions are co-ordi- 
nated. 

2. Axons and collaterals from neighboring segments of the 
cord, and from the cerebellar, medullary, pontine, tectal, and 
ganglional centers reach these cells, either directly or by way of 
the cells of the middle of the spinal gray crescent. By this means 
the more complex reflexes and the reactions characteristic of the 
emotional and instinctive activities are probably carried. 



GENERAL AND OSTEOPATHIC. 469 

3. Fibers of the direct and the crossed pyramidal tracts 
carry impulses from the precentral areas of the cortex to the 
spinal cells, either directly or by way of the cells of the center of 
the crescent. By this means the volitional impulses are carried. 

These structural relationships of the anterior horn cells under- 
lie the varied functions which are performed by them. So long 
as the impulses reaching these cells are normal and the cells them- 
selves are normal in structure and environment, then the activi- 
ties are for the best good of the body. But when any of the path- 
ways for the normal nerve impulses are impeded, or when the 
blood is deficient in quality, or when the flow of the blood is in 
any way disturbed, then the activity of these cells is not that 
associated with the best reaction of which the body is capable. 
These disturbances in the nerve relationship or the nutrition of 
the nerve cells are caused by a number of conditions — poisons 
of various kinds in the body, injuries, pressure from tumors, 
hemorrhages, etc. — and not by any means the least, the presence 
of bony lesions. 

The centers which control the visceral muscles, the secretion 
of the glands, the muscles of the walls of the blood vessels, and 
the muscles which raise the hairs, all are placed in the lateral 
horns of the cord whose cells send their fine axons into the sympa- 
thetic ganglia. From these ganglia other axons pass, which have 
no medullary sheaths, to terminate in the non-striated muscles 
and glands. 

The cells of the lateral horns of the cord are controlled by 
nerve impulses from the following sources: — 

1. Nerve impulses from the sensory neurons of the first 
or higher orders, of the same or neighboring segments of the cord, 
bring about the visceral or somato-visceral reflex actions. B} r 
this means, normally, the body is enabled to act as a unit in the 
presence of varying bodily conditions. Abnormally, by this 
means, the effects of bony lesions and of irritations from diseased 
viscera are enabled to perpetuate the abnormal condition and to 
vary the visceral and vascular activities in a manner which is, 
often, not for the best good of the body. 



470 physiology: 

Descending impulses from the higher centers, certainly 
from the centers of the medulla, pons, and mid-brain, and prob- 
ably of the cerebellum and ganglional centers, bring the activities 
of these spinal centers into harmony with the needs of the entire 
body, in its complex reflex actions and in its instinctive and emo- 
tional states. 

The activity of these viscero-motor, vasomotor, and secre- 
tory centers may be affected abnormally by the bony lesions 
already mentioned in connection with the cells of the anterior 
horns, and by the quality and the pressure of the blood flowing 
through them. Since the nutrition and circulation of the entire 
body depend to so great a degree upon these visceral centers, it 
is evident that any mal-function of these centers must in turn 
act upon them in a detrimental manner. 



CHAPTER XLIX 
THE SPINAL CENTERS. 

The centers of the spinal cord may be divided for conven- 
ience into groups, though it must be remembered that this division 
is largely empirical. The most convenient grouping includes 
an upper cervical, lower cervical, upper thoracic, lower thoracic, 
and the lumbo-sacral groups of centers. 

The Upper Cervical Group.— The centers of the upper 
cervical cord lie in the gray matter of the first to the fourth cervical 
segments, inclusive. This occupies the upper cone of the cervical 
enlargement. 

The anterior horn is large and broad. Its mesial cell column 
innervates the trunk muscles, as does the entire column of these 
cells throughout the spinal cord. In the upper cervical group 
these muscles include, by the posterior primary divisions of its 
nerves, the superior and inferior oblique, the rectus capitis posticus 
major and minor, the complexus, trachelo-mastoid, the splenius 
and semi-spinalis, the multifidus spinse, the transversalis cervicalis, 
the cervicalis ascendens. By the anterior primary divisions 
these centers innervate the splenius, platysma, longus colli, scaleni, 
rectus capitis anticus major and minor, and the rectus capitis 
lateralis, and a part of the sterno-mastoid. The hyoid muscles 
receive, also, fibers from a small cell group in the antero-lateral 
part of this column. 

These cell groups are phylogenetically of great age; they are 
intimately associated with the cells of the posterior and lateral 
regions of the cord, and are easily affected by sensory impulses 
from the viscera and skeletal structures innervated, either di- 
rectly or indirectly, by way of these segments. They are found 
abnormally contracted under many very varied abnormalities 

471 



472 PHYSIOLOGY : 

of the cranial, cervical, and thoracic viscera, and also in certain 
abdominal and pelvic diseases. 

The antero-lateral cell group of the anterior horn sends axons 
to the larger and more superficial muscles. These cells are less 
intimately related to the cells of the other areas of the spinal 
gray matter, and thus are less frequently stimulated by sensory 
impulses from diseased viscera or abnormal conditions in the 
body. The levator scapulae, teres major and minor, supraspinatus, 
and the rhomboids are innervated by these nerve cells. They 
are of a rather late phylogenetic development, and are less often 
subject to reflex disturbances in tone than are the deeper 
muscles. 

The lateral horn is not well developed in the upper cervical 
cord. Cells apparently homologous with the lateral-horn cells 
innervate chiefly the sterno-mastoid and the trapezius, by way 
of the spinal portion of the eleventh cranial nerves. These muscles 
are especially subject to reflex contraction. The trapezius and 
the sterno-mastoid are homologous with the muscles of the ancient 
gill-cleft musculature, and are in this way related to visceral 
muscles. This primitive relationship doubtless affords the struc- 
tural basis for the remarkable susceptibility of these neurons to 
stimulation from sensory impulses from viscera, skin, articular 
surfaces, and other tissues innervated from the upper cervical 
sensory nerves. 

The posterior horn of the upper cervical cord is capped by 
the substantia gelatinosa, in which the descending fibers from the 
fifth cranial nerves terminate. The sensory fibers of the eighth, 
ninth, and tenth cranial nerves also send collaterals and terminals 
into the gray matter of these segments. The sensory fibers of 
the upper cervical segments innervate the skin over the back 
of the head, the neck, and over the scapula and shoulders. 

Impulses from the skin of these regions, from the correspond- 
ing articular surfaces of the vertebrae, or from the areas supplied 
by the fifth, ninth, tenth, and part of the eighth cranial nerves, 
may affect the activities of the upper cervical centers. It must 
be remembered that sensory impulses from the tissues innervated 



GENERAL AND OSTEOPATHIC. 473 

by the sensory fibers of the fifth, eighth, ninth, and tenth cranial 
nerves, as well as from the first to the fourth cervical nerves, may 
cause abnormal contractions of the muscles already named as 
being innervated from these centers; and it must also be re- 
membered that the abnormal muscular contractions, especially 
of the muscles of the anterior neck region, may be responsible 
for such pressure upon the nerves, ganglia, blood vessels, lymph- 
atics, etc., of the neck that serious disturbances may result. 

The Lower CervicaS Group. — The lower cervical group 
includes the nerve centers located in the fifth cervical to the first 
thoracic segments of the cord, inclusive. These segments in- 
clude the lower cone of the cervical enlargement. The anterior 
horns are large and broad, and they include a lateral and an anter- 
ior cell mass, as is the case in the upper cervical group. 

The mesial cell group represents* the older structure, phylo- 
genetically. Their central relationships are very complex and 
they are very liable to the effects of disturbed sensory impulses. 
The axons from the mesial cell innervate the muscles of the trunk, 
including the semispinalis, multifidus spinse, trachelo-mastoid, 
scaleni, longus colli, cervicalis ascendens, transversalis cervicis, 
complexus, and splenius. 

The lateral cell mass includes several groups whose relations 
have not yet been fully determined. The cells send axons to the 
muscles of the shoulder girdle and the arms and hands. These 
include the teres major and minor, supraspinatus and infraspinatus, 
rhomboid, anconeus, subscapularis, serratus magnus, pectoralis 
majcr and minor, coraco-brachialis, deltoid, biceps, triceps, 
brachialis anticus, supinators longus and brevis, latissimus dorsi, 
the pronators, extensors and flexors of the wrists. and fingers, 
the lumbricales and interossei, the thenar and palmar muscles. 

The cells of the lateral cell masses are less intimately asso- 
ciated with otner cell groups of the cord, and are less easily sub- 
ject to the effects of sensory impulses than are the cells of the 
mesial cell mass. 

The viscero-motor column, or the lateral horn of the cord, is 
scarcely represented in this group of nerve centers. A few fibers 



474 PHYSIOLOGY : 

enter the phrenic nerve from the upper part of the group, and a 
few assist in forming the eleventh cranial nerve. The first tho- 
racic and probably the seventh cervical segments appear to con- 
tain a part of the cilio-spinal center, or to be in close relationship 
with the cells of this center. 

The posterior horn is still capped by the substantia gelatinosa,, 
and probably some of the descending fibers of the fifth cranial 
nerve reach these segments. It is certainly true that impulses 
from the area of distribution of the fifth cranial nerve initiate 
reflex contractions of the muscles innervated from the mesial 
cell mass of these segments. The sensory fibers entering these 
segments innervate the skin over a small part of the anterior 
and the posterior wall of the thorax, the arms, hands, and fingers ; 
the muscles innervated by the same segments; the articular 
surfaces of all the bones moved by these muscles; the meninges 
of the corresponding spinal segments. No viscero-sensory nerves 
have been described, except as has already been mentioned, in- 
directly, by way of the descending fibers of the fifth and possibly 
other cranial nerves. 

Lesions affecting the articular surfaces of the fourth cervical 
~to the fifth thoracic vertebrae, the first ribs, clavicle, or scapula 
may cause abnormal contractions of the muscles named, and 
may thus interfere with the shape and size of the thoracic inlet. 
Thus the circulation through the viscera of the head and neck 
may be interfered with. 

The Upper Thoracic Group. — The upper thoracic group 
of centers lies within the gray matter of the second to the sixth 
thoracic segments of the cord. Probably these centers intrude 
upward into the lower cervical group, and downward into the 
lower thoracic group, to a certain extent. 

The anterior horns of these segments are long and narrow. 
It includes cells homologous with the mesial cell group of the 
cervical and lumbar regions. These cells are easily affected by 
abnormal sensory impulses from diseases of the viscera innervated 
from these segments. The reflex contraction of the intercostal) 
muscles in pulmonary tuberculosis is recognized by most phy- 



476 physiology: 

sicians, whether they realize the full significance of the relation- 
ship or not. 

The cells of the anterior horns send axons to the semispinalis 
dorsi, spinalis dorsi, multifidus spinse, rotatores spinse, inter- 
transversales, interspinales, longissimus dorsi, accessorius, leva- 
tores costorum, serratus posticus, the intercostal muscles of the 
corresponding segments, and, by a few fibers, to the external 
oblique. 

The lateral horn is well developed. It includes cells which 
form a number of viscero-motor centers, all of which are closely 
related and which are controlled, for the most part, in about 
the same manner. All of these receive sensory impulses from the 
area of sensory distribution of the nerves of the upper thoracic 
segments; all are controlled in part by descending impulses from 
the centers in the pons, medulla, mid-brain, cerebral ganglia, and 
perhaps, in part, from the cerebral cortex. 

The Cilio-Spinal Center. — The cilio-spinal centers lie 
within the gray matter of about the sixth or seventh cervical 
segments to the fourth thoracic segment. It seems to be chiefly 
located at about the second thoracic segment. This center pre- 
sents several peculiarities. The impulses from the retina are 
carried to the brain by the optic nerves and tracts, of which about 
one-fourth terminate in the anterior quadrigeminate bodies. 
From these bodies other fibers transmit impulses to the centers 
beneath the aqueduct, and from these, in turn, the tecto-spinal 
tracts carry impulses downward to the cilio-spinal center. De- 
scending impulses from the centers which are concerned in the 
emotional states also are factors in affecting the circulation of 
the orbit, the dilatation of the pupils, and the secretion of tears. 

The fibers from the cilio-spinal centers leave the cord as 
white rami, chiefly with the second and third thoracic anterior 
roots of the cord. They enter the sympathetic chain and pass 
uninterrupted to the superior cervical sympathetic ganglion. Here 
they break up into many fine branches which enter into the forma- 
tion of the pericellular baskets of this ganglion. The axons of 
the sympathetic cells thus affected pass to the orbital structures. 



GENERAL AND OSTEOPATHIC. 477 

The vasomotors follow the carotid artery in part. Other non- 
medullated fibers pass near the Gasserian ganglion and are carried 
to the orbit with the long ciliary nerves. None of these fibers 
enter into physiological relations with the ciliary ganglion, which 
is controlled by the third cranial nerve. The cilio-spinal center, 
by these path-ways, controls the circulation through the orbital 
tissues, and the tear glands, the dilator muscles of the pupil, 
the non-striated fibers of the levator palpebrarum, and the 
non-striated muscle fibers of the capsule of Tenon. 

Centers Controlling the Cranial Viscera and Blood 
Vessels. — The centers which control the circulation through the 
cranial structures and the secretion of the glands of the head and 
neck are located chiefly in the gray matter of the upper thoracic 
segments of the cord. The vasomotor centers for the head region 
are placed, for the most part, in the' lateral horns of the first to 
the fourth thoracic segments, though neighboring segments may 
include cells associated with this function. The axons of cells 
of this region pass as white rami communicantes into the sympa- 
thetic chain and pass in this chain to the superior cervical sympa- 
thetic ganglion, where some of the fibers terminate, and thence 
to the smaller ganglia in the cranial cavity, where other fibers 
terminate. The non-medullated fibers which are the axons of 
sympathetic cells pass to the walls of the blood vessels, the viscera, 
the pilomotor muscles, and other tissues of the head and neck 
region. The presence of vasomotor nerves in the brain has been 
a matter of dispute; recent experiments appear to indicate their 
presence. The presence of vasomotor nerves in the cerebral 
and spinal meninges is unquestioned. 

The nerves controlling the activities of the glands and the 
non- striated muscles of the head follow about the same pathway, 
and are liable to practically the same series of effects under patho- 
logical conditions. 

Secretory and Vasomotor Centers for the Throat and 
Neck. — The centers controlling the circulation through the tissues 
of the neck and the throat and the secretion of the glands of this 
region are placed in the gray matter of the second to the fifth 



478 PHYSIOLOGY : 

thoracic spinal segments, with probably some intrusion upon 
neighboring segments. The white rami fibers originating in 
these segments, carrying impulses destined for the viscera and 
blood vessels of throat and neck, pass by way of the sympathetic 
chain to the middle and superior cervical ganglia, where they 
terminate in the pericellular baskets. The gray fibers, which are 
the axons of the sympathetic cells, join the cranial and the cer- 
vical nerve trunks or become associated with the arteries, and 
are thus carried to the areas of their distribution. 

Brachial Vaso-motor and Viscero-Motor Control. — 
The blood vessels, the sweat and sebaceous glands, and the pilo- 
motor muscles of the shoulder girdle, the arms and hands, are 
controlled by centers located in the third to the fifth thoracic 
segments, with probably some intrusion upon neighboring seg- 
ments. Nerve impulses for this purpose are carried by the 
white rami of these segments by way of the sympathetic chain 
to the ganglion stellatum. Rarely, in the cat and the dog, the 
middle cervical ganglion appears to be associated with this series. 
From the ganglion stellatum gray fibers pass to the nerves of the 
cervical plexus, and thus, with them, to the tissues named. The 
palmar surfaces of the tips of the fingers appear to receive no 
vasomotor nerves, and the palms are very scantily supplied. 

Spinal Cardiac Centers. — The centers concerned in in- 
creasing the rate and force of the heart's beat lie within the second 
to the fourth thoracic segments with outlying cells in the first, 
fifth, and sixth segments. The fibers carrying the impulses con- 
trolling these functions leave the cord with the anterior roots, 
pass as white rami into the sympathetic chain, and travel upward 
to the cervical region. They terminate by forming synapses 
with the cells in the superior, middle, and perhaps the inferior 
cervical ganglia. The gray fibers join the vagus, and are carried 
in this nerve to the cardiac ganglia. It is not probable that the 
gray fibers form synapses with the cells of the intrinsic cardiac 
ganglia; it is known that the vagus fibers themselves do thus 
terminate, at least in part. ' 




Fig. 64. — Control of the Brachial Circulation. (Courtesy of Dr. Burns.) A, 
anterior root; B, anterior horn cell; C, sensory cell; D, sensory axone; E dividing axone; 
F, posterior root; G, gray fiber; H, sympathetic ganglion; I, sympathetic cell; J, white fiber; 
K, anterior root; L, anterior horn cell (somatic efferent) ; M lateral horn cell (visceral efferent) ; 
N, sensory fiber; O, sensory cell; P, sensory axones; Q, dividing axone. 



480 PHYSIOLOGY ! 

Sensory fibers for the heart follow the pathway just outlined, 
except that they originate in the ganglia on the posterior roots 
of the spinal nerves. They send axons into the spinal cord by 
way of the posterior roots. 

There is some evidence in favor of the view that vasomotor 
nerves for the heart originate in the same spinal segments, and 
are carried by the same pathway as the accelerator and augmentor 
nerves. This matter is yet to be demonstrated more fully. 

The Pulmonary and Pleural Vasomotors. — The lungs 
receive vasomotor impulses from centers rather broadly segmental 
in localization. The upper lobes are controlled from the upper 
thoracic centers, the middle from the mid-scapular region, and 
the lower from the fifth and sixth, perhaps also the seventh, tho- 
racic segments of the spinal cord. The medullated fibers from 
these centers enter the sympathetic chain, as white rami; they 
appear to terminate in the ganglia of the upper thoracic and cer- 
vical portion of the sympathetic chain. The axons from these 
ganglia pass partly by way of the vagus and partly by way of the 
aortic plexus to the blood vessels of the lungs and the pleura. It 
must not be forgotten that the size of the pulmonary vessels is 
subject to variations due to variations in the systemic circulation, 
as well as to direct vasomotor control, and that the effects produced 
by changes in systemic pressure conditions may be more pro- 
nounced than those due to the more direct innervation. 

Control of the Upper Thoracic Centers. — These centers 
of the upper thoracic region, those controlling the skeletal muscles 
of the shoulder girdle, the circulation, the secretion, and the visceral 
activities of the tissues of the head, face, neck, and thorax, are 
themselves controlled by impulses from the sensory nerves of 
the same and adjacent segments of the cord, by sensory impulses 
from the cranial nerves, and by descending impulses from the 
medullary, pontine, tectal, ganglional and cortical centers. Sen- 
sory impulses from the skin and superficial muscles affect the 
functions of these centers to a certain extent; sensory impulses 
from the deeper muscles, the viscera, and the articular surfaces 
of the bones related to these tissues affect the centers in a marked 



GENERAL AND OSTEOPATHIC. 481 

degree. The place of bony lesions of the upper thoracic verte- 
brae in the etiology of congestion of the eyes, the naso-pharynx, 
the mucous membranes of the throat, the meninges and all tissues 
of the head, should not be forgotten. That bony lesions of this 
area are an efficient factor in the cause of adenoids and nasal 
polyps is beyond question. The abnormal dilatation of the pupil 
due to lesions affecting the cilio-spinal center is often a cause of 
eye strain, and, through the nervous disturbances thus produced, 
of functional variations in the muscles of accommodation. 

The nutrition of the skin and the muscles of the arms and 
hands may be affected by bony lesions of the upper thoracic ver- 
tebrae. Circulatory conditions of the hands, with ocular disturb- 
ances, not to be distinguished clinically from the early stages of 
Raynaud's disease, are found associated with lesions of the fourth 
and third thoracic vertebrae, and such patients have recovered 
apparently completely after the correction of the lesions. Weak- 
ness and inco-ordination of the muscles, persistent eczemas, 
recurrent infections, and many disturbances in the shoulder 
girdle, arms, and hands may be in part due to bony lesions of the 
upper thoracic vertebrae, the ribs, scapula, or clavicle. When 
the bones of the upper extremities are broken or dislocated, or 
when injuries of any kind are present, bony lesions affecting the 
circulation through the injured parts may retard recovery. The 
care of all traumatic affections of the upper part of the body should 
include the correction of lesions of the cervical and upper thoracic 
vertebrae, and the other bones related to these. 

The Lower Thoracic Group. — The centers of the lower 
thoracic group include those lying in the gray matter of the sev- 
enth thoracic to the first lumbar segments, inclusive, with prob- 
ably outlying cells in adjacent segments. 

The area of gray matter of the lower thoracic region is rather 
small. Both the posterior and the anterior horns are long and 
narrow; the lateral horn is very well developed. 

The anterior horn includes the cells only of the mesial group. 
These send axons to the longissimus dor si, multifidus spinae, 
accessorius, latissimus dorsi, quadratus lumborum, pyramidalis, 



482 PHYSIOLOGY : 

cremaster, psoas major and minor, the corresponding inter- 
costal and interchondral muscles, and the abdominal muscles. 
All of these muscles are easily affected by sensory disturbances 
initiated either by visceral diseases or by the irritation from bony 
lesions. They are normally kept in a condition of tone by the 
normal impulses from these sources, and the abnormal reflexes 
caused by abnormal sensory stimulation should be considered 
as merely an extravagant increase in the reflex actions which 
have so beneficent an effect upon the muscles under normal con- 
ditions. 

The visceral centers of the lower thoracic group are many. 
The nerve impulses from these segments to the viscera are carried 
by about the same pathways in all cases. There are two groups 
of medullated fibers leaving the spinal cord, and the relationships 
between these groups is not well known. White fibers leave the 
lateral horns of the cord by way of the anterior roots, and pass 
as white rami into the sympathetic chain, where they terminate 
by forming the pericellular networks around the sympathetic 
cells. The gray fibers from the sympathetic ganglion cells pass 
partly by the splanchnic nerves and partly by way of the peri- 
vascular plexuses to the viscera and blood vessels. Another 
group of cells, also in the lateral horns, sends white axons by 
way of the anterior roots, and these fibers pass directly to the 
larger sympathetic ganglia in the abdominal cavity, such as those 
of the solar plexus, etc. The splanchnic fibers terminate in these 
ganglia, as do the white rami fibers in the lateral chain of sympa- 
thetics. It seems true that the white rami and splanchnic fibers 
all terminate in some sympathetic ganglia and also that not more 
than one relay occurs between the center in the cord and the struc- 
tures to be innervated. Any given medullated fiber may branch into 
fibrillse, and these may enter into the pericellular baskets around 
several sympathetic cells, and may even send different branches 
into different sympathetic ganglia. It is true also that several 
white fibers may unite in forming the basket around a single sympa- 
thetic nerve cell. The great complexity of the functions controlled 
by way of the lower thoracic centers and the sympathetic ganglia 



GENERAL AND OSTEOPATHIC. 483 

is thus seen to depend upon an equally complex neuronic relation- 
ship. The presence of the vagus nerves adds further complexities. 

The Gastric Center. — The paths of the impulses concerned 
in governing the movements, circulation, and secretion of the 
stomach have not yet been well worked out. A number of puz- 
zling facts are known concerning the functions of these nerves. 
The center controlling these functions lies in the fifth to the seventh 
thoracic segments, with some intrusion upon the fourth and eighth 
segments. The impulses from these centers are carried partly 
by the splanchnics, partly by the sympathetic roots of the vagus, 
and partly by the arterial plexus. The functions of these nerves 
and the centers from which they originate are affected in a marked 
degree by variations in the amount of carbon dioxide in the blood 
and probably by varying amounts of other constituents of the 
blood. The physiological conditions of these structures also ap- 
pear to cause more marked variations in function on the part of 
the gastric nerves than is recognized in studying the nervous 
control of other organs. 

Lesions involving the vertebrae, and more rarely the ribs, 
associated with the spinal segments mentioned are usually found 
associated with varying degrees of gastrectasis, gastritis, or hyper- 
or hypo-chlorhydria, and with other symptoms, referable to dis- 
turbed nervous control. In the presence of gastric ulcer, cancer, 
or any structural lesions of the stomach, the reflex muscular con- 
tractions in the middle thoracic region of the back are usually 
painful, and are also an increased cause of abnormal gastric func- 
tion. The relief of the bony and muscular lesions associated with 
incurable stomach diseases is often a source of great relief to the 
patients; the progress of the disease may be hindered, and life 
is made much easier. 

Centers for Spleen, Liver, and Pancreas. — The spleen, 
liver and pancreas are controlled by centers placed in the gray 
matter of the sixth to the tenth thoracic segments of the spinal 
cord, with some cells scattered both upward and downward into 
neighboring segments. 



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GENERAL AND OSTEOPATHIC. 485 

The spleen has its capsular layer of muscle fibers innervated 
by the upper and middle splanchnic nerves, by way of the solar 
plexus. Variations in the tone of the spleen, and thus in the cir- 
culation of the blood through the abdominal viscera, may be caused 
by lesions of the vertebrae of the lower thoracic region, especially 
of the tenth thoracic. The vasomotor nerves for the splenic 
vessels are carried by the same pathway. The vagus appears 
to have less effect upon the spleen than it has upon the other 
abdominal viscera. The enlarged spleen in malaria and in spleno- 
medullary leukemia has been found associated with lesions of 
the ninth and tenth thoracic vertebrae and with increased sensi- 
tiveness and reflex contractions of the deeper spinal muscles 
innervated from these same segments of the cord. 

The liver appears to have all of its varied functions subject 
to nervous control. The place of the vagus has not been well 
determined; it is known to exercise some control over hepatic 
functions. The spinal centers have been shown to modify the 
secretion of bile, the circulation both of the hepatic and the portal 
vessels, the formation of glycogen and urea, and the peristalsis 
of the bile ducts. All of these functions are also, in some degree, 
modified by impulses carried by way of the vagus nerves, and the 
entire nervous mechanism of the liver appears to be under the 
especially efficient control of centers in the medulla. 

The nervous control of the pancreas has not been well studied. 
The experiments upon animals demonstrated increased redness 
after bony lesions of the tenth, ninth, and sometimes the eighth 
thoracic vertebrae. Patients suffering from diabetes mellitus 
have usually had lesions of the tenth and sometimes adjacent 
vertebrae. 

Centers for Intestinal Control. — The intestines appear 
to be controlled by a series of centers which bear a rather roughly 
segmental relationship to the different parts of the tract. These 
centers lie in the gray matter of the cord of the ninth thoracic 
to the second lumbar segments, with a certain amount of intrusion 
upon the segments adjacent, both above and below. The im- 
pulses are carried by way of the splanchnics and the solar plexus, 



486 physiology: 

and partly by way of the aortic plexus. The influence of the 
vagus should not be forgotten. 

The artificial bony lesion in animals under anesthesia is 
followed by results similar to those found in patients suffering 
from the effects of bony lesions in the lower thoracic region. These 
include the formation of rings of persistent contraction in the 
intestinal wall which are resistant to all ordinary methods of 
purgation, increased peristalsis, lessened tone of the intestinal 
muscles, with accumulation of carbon dioxide in greatly increased 
quantities; pronounced redness of the intestines, with later ap- 
pearance of venous congestion; and sometimes by reversed peri- 
stalsis. 

The centers controlling the intestinal movements, secretion, 
and circulation, may be affected by impulses reaching them from 
the various viscera of the abdominal cavity, by impulses from 
abnormal articular surfaces, muscles, or, in less degree, the skin 
over the corresponding areas of the back and abdomen, and by 
impulses descending from the medulla, pons, mid-brain, ganglional 
centers, and possibly from the cerebellum. The place of emo- 
tional disturbances in causing either diarrhoea or constipation 
is well known. Volitional impulses are not efficient stimuli for 
the intestines, but volitional impulses may affect the abdominal 
and lumbar muscles, and the increased tone of these muscles 
is almost always associated with increased tone, and thus usually 
with increased activity, of the intestinal muscles. 

The Renal Centers. — The kidneys appear to act altogether 
in accordance with the speed of the circulation through them. 
Secretory nerves have not been demonstrated for them, nor is 
there any fact in the examination or treatment of patients which 
gives indication of secretory nerves for the kidneys. The circu- 
lation through the kidneys, locally, is governed by centers in 
the eleventh and twelfth thoracic segments of the cord. These 
centers appear to be more strictly limited to the segments named 
than are other spinal centers. The variations in systemic blood 
pressure are important factors in modifying the secretion of the 
kidneys, also. Lesions affecting the articular surfaces of the 



GENERAL AND OSTEOPATHIC. 487 

eleventh and twelfth vertebrae, or the eleventh or twelfth ribs are 
apt to affect the circulation through the kidneys, and thus to 
modify the character of the urine. Lesions affecting the systemic 
blood pressure are also factors in diminishing the efficiency of 
the kidneys as organs of elimination. 

The Suprarenals. — The suprarenal capsules receive both 
secretory and vasomotor nerves from the eleventh and twelfth 
thoracic segments. These centers are not very well understood, 
but it is known that descending impulses from the ganglional 
and probably other higher centers affect the adrenal secretions. 
Bony lesions of the vertebrae and ribs innervated from the same 
segment affect the circulation through these glands, and this 
probably affects also the amount of their internal secretion carried 
into the circulating blood. Stimulation of the sensory nerves 
of these segments in human subject's causes a rise of blood 
pressure which may persist for some hours. In clinic patients 
the correction of lesions of this region is usually followed by an 
increased tone of the vascular and cardiac muscles. 

The Reproductive Glands. — The circulation through the 
ovaries and testes is controlled by nerve impulses from the tenth 
thoracic to the second lumbar segments, chiefly by way of the 
lesser splanchnic nerves, the aortic and solar plexus. These 
centers are affected greatly by descending impulses from the 
higher centers, and the impulses thus carried usually affect also 
the muscles innervated from these segments. The place of erotic 
literature or thoughts or circumstances in modifying the circu- 
lation through the reproductive glands must not be forgotten in 
the care of patients suffering from diseases of these organs. Bony 
lesions affecting the vertebrae associated with the ninth thoracic 
to the second lumbar nerves may seriously impede the circulation 
through them, and thus may be an important factor in causing 
or in perpetuating diseases of the ovaries or the testes. The 
ovaries are more seriously disturbed by abnormal circulatory 
conditions, chiefly for anatomical reasons. 

Secretory nerves have not been demonstrated for these glands, 
though certain facts of clinical experience seem to indicate that 



488 physiology: 

the internal secretions, at any rate, may be under nervous control. 
Probably circulatory changes may modify the amount of internal 
secretions in the blood stream. 

The Lumbo-Sacral Group. — The centers of the lumbo- 
sacral areas include those lying below the second lumbar segments. 
These segments give rise to no white rami fibers, though the 
nervus erigens probably is homologous with the splanchnics. 

The lumbar cord is characterized by its short, broad horns, 
and by the comparatively scanty white matter around the 
periphery. 

The anterior horns, like those of the cervical region, include 
several groups of cells, whose axons innervate the skeletal muscles 
of the legs and the pelvic girdle. 

The axons of the mesial cell group innervate the multifidus 
spinse, interspinales, psoas major and minor, gemelli, glutei, 
obturators, pyriformis, and the lower parts of the abdominal 
muscles. 

The axons of the cells of the lateral cell group of the anterior 
horn innervate the muscles of the thigh, leg, foot, and toes. 

The location of the cells which supply a number of the pelvic 
muscles is not yet thoroughly demonstrated. They bear certain 
resemblances to visceral muscles, in function and in relations, 
yet they also have some characteristics of skeletal muscles. The 
phylogeny of these muscles and of their nervous control need 
much study. The muscles of this type are the cremasters, sphinc- 
ters ani, levator ani, compressor urethrae, ischio-cavernosus, 
transversus perinaei, sphincters vesicae, sphincter vaginae. 

The lateral horns of the lumbar cord are wanting or very scan- 
tily represented. In the sacral region a cell group probably holomo- 
gous with the lateral horns of the thoracic region gives origin to 
the nervus erigens. 

The posterior horns are short and broad. The sensory 
ganglia send their fibers as posterior roots into the cord, and the 
axons of these send terminals and collaterals into the gray matter 
of all regions. The peripheral fibers of the sensory ganglia of 
the lumbar and sacral cord are distributed to the skin over the 



GENERAL AND OSTEOPATHIC. 489 

front of the body below the pelvis, including the external genital 
organs, and over the back of the body below the crest of the ilium 
to the muscles and tendons subject to the motor control of these 
segments; to articular surfaces of all the joints moved by these 
muscles, and to the viscera controlled by the centers of the lumbo- 
sacral group. 

The motor cells of the lumbo-sacral group are under the 
control, in part, of the sensory impulses reaching these and ad- 
jacent spinal segments; of descending impulses from the medullary 
and other higher centers; of volitional impulses from the pre- 
central area of the cerebral cortex of the opposite side; and from 
the various ganglia in which emotional and instinctive functions 
are controlled. 

Bony lesions of the lumbar vertebrae, of the sacrum, of the 
coccyx, and of the innominates may initiate sensory impulses 
subversive of normal activities of these centers. Lesions of the 
femur, tibia, fibula, patella, and ankle and foot bones are less 
likely to produce reflex disturbances, though lesions of these 
bones, being subject to pressure in walking and standing, and being 
capable of affecting the spinal curvatures, are more often the cause 
of harmful reflexes than are the corresponding bones of the arms. 

The Ano-Spinal Center.- — The ano-spinal center lies in 
the lumbar enlargement, it appearing to occupy several segments. 
Both inhibitory impulses to the anal sphincters and stimulating 
impulses to the muscular fibers of the lower colon, sigmoid, and 
rectum are sent from this center, chiefly by the descending associa- 
tion tracts and the third or fourth sacral nerves; or by way of 
the white rami of the first or second lumbar nerves, the sympa- 
thetic ganglia, and the inferior and the hypogastric plexuses. 
Association tracts also carry impulses which regulate the tension 
of the intercostals, the diaphragm, and the abdominal muscles. 
The ano-spinal center is very closely related to the other lumbo- 
sacral centers, especially those concerned in micturition, erection 
and parturition. 

An important point in the treatment of certain diseases 
lies in the fact that reflex contractions of the anal sphincters may 



490 physiology: 

result from bony lesions of the sacrum, innominates, and coccyx. 
Others lesions may also be associated with this condition. The 
loss of tone of hemorrhoidal veins may depend, in part, upon 
lesions of the same or neighboring bones. Abnormal sensory 
impulses from injured pelvic tissues and from diseased tissues in 
the area of distribution of the lumbo-sacral sensory nerves, may 
also be concerned in modifying the functions of the muscles of 
defecation, and of the circulation through the anal tissues and 
the surrounding structures. 

The Vesico-Spinal Center. — The control of micturition 
is by way of about the same paths, and the center is located in 
the same spinal segments. The enuresis of children, and a lack 
of bladder control both in children and adults, may be due to 
lesions of the lumbar and pelvic bones, or to peripheral irritations 
such as worms, adherent clitoris or prepuce, or any other factor 
of irritation to the sensory nerves of the same segments. 

The Genito-Spinal Center. — This center has been demon- 
strated for male dogs and for men, but no homologous center has 
been demonstrated for females. Impulses from this center in- 
hibit the activities of other lumbo-sacral centers, and of certain 
medullary and thoracic centers. The efferent nerves are partly 
somatic and partly visceral. The somatic nerves pass from the 
anterior horn cells directly to the skeletal muscles concerned in 
coition; the impulses for the blood vessels and the visceral muscles 
concerned probably pass by way of the erection center. 

The Erection Center. — The center which controls the 
phenomenon of erection lies in the lower part of the lumbar cord. 
It appears to be controlled normally by the genito-spinal center, 
but under abnormal conditions it may act independently. It 
is more directly under the control of sensory impulses than is the 
genito-spinal center, but it exerts a less pronounced inhibitory 
effect upon other centers, at least when it is abnormally and 
independently stimulated. Bony lesions of lumbar and pelvic 
bones, abnormal sensory irritations, etc., may cause priapism in 
adults or may be responsible for abnormal circulatory conditions 
in the external genital organs. These abnormalities, in turn, 



492 physiology: 

may be important factors in causing bad habits in children or 
vicious tendencies in either children or adults. 

The Parturition Center. — The parturition center appears 
to be more directly concerned in the regulation and the control 
of labor than its initiation. It has been found difficult, in exper- 
imenting upon animals, to initiate anything like efficient labor, 
pains before term, or to hasten labor to any great extent, by 
stimulating the lumbar centers. Slight increase in the process 
and slight dilatation of the cervix were produced. From the 
experiments performed it appears that the place of bony lesions 
in interfering with labor lies more in the disturbed developmental 
and the nutritional and circulatory conditions than in the actual 
birth process. This does not, of course, apply to the gross pelvic 
deformities which offer mechanical obstruction. Experiments 
in this study are difficult, and much more clinical and experimental 
evidence is needed. 

Vasomotors for Pelvic Organs. — The circulation through 
the pelvic organs is governed partly from the tenth thoracic and 
neighboring segments (ovaries and testes, especially) and partly 
from the lumbo-sacral centers. The nervus erigens, from the 
sacral lateral-horn cells, terminates in the hypogastric plexus, and 
the gray fibers from these ganglion cells innervate the blood vessels 
of the lower pelvis and the external genital organs. Reflex dis- 
turbances of the circulation through these organs and their neigh- 
boring tissues may be caused experimentally by bony lesions in 
the area of the sensory distribution. Clinically, disturbed cir- 
culatory conditions may often appear to be due to these lesions 
and recovery may occur with no other treatment than the cor- 
rection of these lesions. These facts should not lead to the neg- 
lect of other causes of diseases of these organs. 



CHAPTER L. 



THE PHYSIOLOGY OF CONSCIOUSNESS. 



Because of the vast amount of speculation regarding the 
relationship of mind and body, and because of the failure of mere 

philosophical specula- 
tions to meet the de- 
mands of rational 
methods of approach- 
ing the diagnosis and 
treatment of mental 
diseases, a series of 
tests was begun in the 
attempt to discover 
whether or not those 
phenomena called 
consciousness might 
be subject to the same 
laws as those which 
govern the physiolog- 
ical relationships of 
other organs of the 
body. 

The facts already 
known regarding the 
activities called con- 
sciousness may be 
briefly given. It is 
known that, in the 
human subject at 
least, the activity of 
493 




Fig. 67. — Spindle and polymorphic cells from the ex- 
ternal layer of the human cortex. These cells are not fre- 
quently found in the brains of lower animals, nor in the 
brains of idiots. They are poorly developed in young chil- 
dren, and are most" plentiful and best developed in the over- 
flow areas of the adult human cortex. They are also 
plentifully found in the olfactory cortex. 



494 



PHYSIOLOGY I 



the neurons of the cerebral cortex is essential to consciousness. 
The activities of other parts of the nervous system may be 
essential to the normal condition of the body, but these activities 
alone are not able to initiate or to modify consciousness. Con- 
sciousness is certainly known to be a phenomenon associated 







Fig. 68. — Cells from the cortex of the rabbit's brain. 380 diameters. The irregular 
appearance of the pyramidal cells and short dendrites should be noted. 



with the activity of the cortical neurons, and to depend abso- 
lutely upon this activity. Of the cortical neurons, there is much 
evidence in favor of the view that the small cells of the extreme 
periphery are those most directly concerned in producing con- 
sciousness. The neurons of the deeper layers of the cortex are 
efficient in transmitting and co-ordinating the nerve impulses 
to and from the external layer, but these appear to be capable 
of acting independently, without arousing consciousness. 







Neuroglia 



Stratum zonale 



Small pyr. 



Medium pyr. 



' Ext. layer pyr. 
--•»->■ Baillarger's line 



*■- - - Small pyr. and 

polym. 



Inverted pyr. 



... Int. lar. pyr. 



Polymorphic 



White matter 



Fig. 69. — Diagram of the layers of the typical cerebral cortex. The neuroglia appears at 
the external surface. The first layer of the cortex contains the spindle and polymorphic cells. 
See Fig. 68. Among these cells the dendrites of other cells, and the axones and collaterals of 
the inverted pyramids of Martinotti branch freely. The layer of small pyramids lies next. The 
dendrites of these reach the first layer; the axones exhaust themselves branching among the 
deeper layers. The third layer is characterized by the medium pyramids. The relations of 
these are as the small pyramids. The fourth layer is characterized by the large pyramids. The 
axones of these may enter the white matter and pass to other parts of the nervous system. The 
fifth layer includes small pyramids and polymorphic cells. The sixth layer contains large 
pyramidal cells, and the axons of these may enter the white matter. The seventh layer con- 
tains spindle and polymorphic cells, whose axons also may reach the white matter and pass t o 
other parts of the nervous system. Small pyramidal cells, multipolar cells, Golgi Type II cells, 
and inverted pyramids may be found through all except the first layer. The line of Baillarger 
coincides with the external layer of large pyramids. 



496 physiology: 

The different parts of the cortex are known to have different 
functions in consciousness. Thus, the stimulation of certain 
areas of the occipital lobe is associated with consciousness of things 
seen, the stimulation of certain areas of the temporal lobe is 
associated with the consciousness of things heard, and so on. The 
structural relationships of the different cortical areas vary accord- 
ing to their varying functions, and the tracts of fibers carrying 
the nerve impulses concerned in the co-ordination of conscious 
activities vary according to the functional relationships of the 
different cortical areas. These statements are made very briefly; 
they rest upon the facts of experimental evidence, of phylogenetic 
studies, of series of developing brains, both under normal and 
abnormal conditions, and of the brains of defectives and of persons 
suffering from various diseases and mutilating accidents. 

The tests performed in the laboratory of physiology of the 
Pacific College are considered in two series: first, a study of the 
effects produced upon the bodily conditions by varying conscious 
states; and second, the manner in which conscious phenomena 
vary during varying physical conditions. 

In both series both normal and abnormal persons were used, 
and of the abnormal persons some were suffering from functional 
and some from structural disturbances. Defective children were 
also included, as well as older persons suffering from diseases of 
the nervous system. The experiments from which these con- 
clusions were deduced included about five hundred tests. 

The " reaction time" is the average time required for the 
simplest association processes. It was determined by first pro- 
nouncing lists of words, in order to decide the pronunciation time 
both of the subject and of the person who gave the words; then 
the person making the test spoke the words in order, and the 
subject answered each word by giving another suggested by the 
one spoken. The time required for speaking fifty words and 
answering with suggested words, less the time required for each 
person to speak fifty words, is the time required for the subject 
to make fifty associations of a very simple order. The average 
time required for each association process is the reaction time for 
the subject under the conditions of the test. 



GENERAL AND OSTEOPATHIC. 



497 




Fig. 70. — Diagram of the elements of the cortex. The arrows show the direction of the 
nerve impulses. A, incoming axon from other parts of the nervous system; B, large pyra- 
midal cell, which may receive the impulse directly from A, or indirectly by the interpolated 
neurons. The axon of B may transmit the impulse thus received to other parts of the nervous 
system, without affecting the neurons of the external layers of the cortex. It is probable that 
consciousness is not affected by these impulses. 

A may transmit the impulses to C, an inverted pyramid of Martinotti, which carries the 
impulses over its axon to the cells of the stratum zonale, D. The dendrites of either the small, 
the medium, the large pyramidal cells, as E, may receive the impulses from D, and the large 
pyramidal cells, as E, may transmit the impulses thus received to other parts of the nervous 
system. 

F, an axon from another part of the nervous system. The impulses carried by F may 
affect the inverted pyramid, G, which in turn may stimulate the cells of the more peripheral 
layers of the cortex, including H, a cell of the stratum zonale. The large, small and medium 
pyramids are affected by the action of H and G, and these affect the cells of the lower layers 
again. The impulse descending from the stratum zonale may be transmitted to other inverted 
pyramids, as G and J, and the impulses thus again carried to the cells of the stratum zonale. 
There is no way of determining the number of times this reaction may occur. It is probable 
that this series of impulses passing around this circular path is the physiological basis of inhibi- 
tion, and thus of the mental process of "thinking things over. " Ultimately the stimulation 
of I, a large pyramid, or of any of the cells of the seventh layer, may carry the impulses to other 
parts of the mervous systen, and the final destination of these must be the motor neurons. 



498 



PHYSIOLOGY : 



For the first series, that is, the study of the effects produced 
upon the bodily conditions by varying conscious states, lists of 
words of varying emotional coloring were used. The subject 
was asked to give synonyms or related terms in answer to the 
words given him. Fifty words are about the limit of usefulness 
in these tests, because the normal person involuntarily assumes 
an attitude of antipathy to the test, and either refuses to con- 
tinue pronouncing the doleful terms, or finds it difficult to refrain 
from joking. 

The effects produced by the gloomy lists upon normal people 
are: 










Fig. 71. — Cells from human temporal lobe, about 200 diameters. A, axons; M, inverted 
pyramids of Martinotti. 



GENERAL AND^ OSTEOPATHIC. 499 

Decreased blood pressure, usually 10-15 m. m. Hg, sometimes 
as much as 40 m. m. ; 

Decreased pulse rate, with occasional irregularities; 

Irregular respiratory movements, with sighing; 

Increased reaction time, usually .5 sec. ; 

Decreased strength in grip, as shown by the dynamometer. 
This is most pronounced in the right hand. 

The effects of the gloomy lists upon persons of a melancholy 
disposition were not marked. In defectives and in people with 
serious diseases of the nervous system no pronounced or constant 
variations occurred. 

Lists of cheerful words were used in the same way. For the 
most part no effects were observed upon the physiological activi- 
ties of normal people by the cheerful lists, doubtless because 
pronouncing the cheerful lists brought no change in the mental 
coloring of normal people — they are normally cheerful, without 
any word lists. A few hypochondriac and neurasthenic patients 
were thus tested. The blood pressure, pulse rate, and muscle 
strength were all slightly increased by the cheerful lists and the 
reaction time was slightly diminished in these persons. Mental 
defectives and persons with serious nervous diseases showed no 
effects produced by the cheerful lists. 

Another series of lists was made up from expressions of 
inefficiency, such as "lazy," " stupid, " " feeble, " etc. These 
ideas produce a slightly diminished muscular tone and the reaction 
time is increased, but the effects upon circulation, etc., were not 
so marked as in the case of the gloomy lists. 

Lists made up of scientific terms — "solstice," "tangent," 
"cosine," "molecule," etc. — gave a longer reaction time, some- 
times slightly raised the blood pressure, often slightly increased 
the muscular tone, but had no very great effect upon bodily activi- 
ties in general. 

Lists of words of strenuous significance exert a noticeable 
effect. Such words as "energy," "violence, "' "pressure, " etc., 
were used. Increased muscular strength results, the blood pres- 
sure goes up, usually about 15 m. m. Hg; the pulse increased 



500 PHYSIOLOGY : 

either in rate or force, and the head showed a more erect position, 
usually. 

In some of the tests the subject simply listened to the reading 
or telling of stories or of articles of varying abstruseness. The 
variations were, on the whole, rather less marked than when the 
giving of suggested words made careful attention on the part of 
the subject an essential part of the experiments. 

The manner in which the pulse, respiration, blood pressure, 
and dynamometer readings varied gave some interesting sugges- 
tions as to the use of these tests in diagnosis of certain types of 
disease. Events which the patient wishes to conceal, or which 
he considers of no importance, or even which he has forgotten, 
may affect these physiological activities and thus be brought out 
by more specific questioning, or may show themselves to the 
physician, who may find it best to conceal his knowledge for a 
time. At any event the value of these, or similar, tests in diag- 
nosis must be recognized. 

The practical application of all this is fairly evident. Patients 
should be induced to maintain a mental atmosphere best adapted 
to their condition. The telling or hearing of accounts of pain 
or disease must be forbidden the sick, usually; children should 
not be permitted to hear or to read about, or to see, anything so 
sorrowful as to affect them seriously; recovery may be hastened, 
in certain diseases, by securing such changes of work or of climate 
or scene as are best adapted to the particular conditions. 

The manner in which bodily states may affect the mental 
states was made the subject of the second series. First, the bony 
lesion was tested. 

Subjects who were normal and rested were chosen. Steady 
pressure at the sides of the spinous processes was, in the first 
group, used as a test of the effects of the bony lesion. In animal 
tests this pressure had been found to give the same results as 
the actual production of a bony lesion, for the most part. The 
axis, atlas, third cervical, second thoracic, and eighth thoracic 
were the vertebrae chosen for the experiments. No subject was 
used for more than one test on any day; all were repeated upon 






GENERAL AND OSTEOPATHIC. 501 

successive days upon the same subject. When the blood pres- 
sure was increased as the result of any given manipulation the 
reaction time was diminished; when the blood pressure was 
decreased the reaction time was increased. When word lists 
of a negative type were used and the blood pressure of the subject 
had been raised in any way, the tendency was for the greater 
number of replies to be of a cheerful type ; when the blood pressure 
was lowered and negative word lists were given, the tendency was 
for the replies to become generally of a more gloomy type. 

In a few patients suffering from arterio sclerosis, in whom 
the blood pressure was already too high, the increasing blood 
pressure brought increased tendency to gloominess; decreased 
blood pressure — i. e., approach to the normal — brought increased 
cheerfulness in the replies. The variations were indicated also 
in the conversation which sometimes was substituted for the 
words with answers. 

Other findings in a series of experiments regarding the more 
complex co-ordinations, under other conditions, give the follow- 
ing results : 

Fatigue increases the reaction time, and also the proportion 
of gloomy replies ; 

Auto-intoxication increases the reaction time ; 

Fasting decreases the reaction time for one or two days, then 
increases it. Cheerful replies are increased at first ; gloomy replies 
after the second or third day. This is evident even when the 
patient shows a very cheerful and merry habit. After urgent 
mental effort, as a final examination, the reaction time was in- 
creased; sometimes it was doubled. The tendency to gloomy 
replies appeared to depend upon other factors than the fatigue 
itself. 

The practical application in this lies in the recognition of 
the facts of the case. To a great extent the slow reaction time, 
the tendency to gloominess and probably to crime, are largely 
dependent upon the condition of the body. The place of the 
bony lesions in the etiology of the milder psychoses must not be 
overlooked. Whether these act directly through abnormal sensory 



502 PHYSIOLOGY I 

irritations, or by means of varying blood pressure, or by means 
of faulty nutrition or assimilation or elimination, or by interfer- 
ing with the normal production of the blood cells in the marrow 
of the flat bones, any rational diagnosis and treatment of functional 
mental disorders must take into account the bony lesions. 






RESULTS OF OSTEOPATHIC RESEARCH. 

By C. A. Whiting, Sc. D., D. 0., 
Pacific College of Osteopathy. 



CHAPTER LI. 
OPSONINS. 

Opsonin is the name given to a number of substances found 
in the serum of the blood which act upon bacteria, increasing their 
susceptibility to the phagocytic action of the white blood cor- 
puscles. Bacteriologists and hsematologists are now of the opinion 
that there are at least two distinct classes of opsonins. The first 
group may be called the natural opsonins. These opsonins are 
quickly destroyed if they are heated to a temperature of 56° C, 
and they seem to act upon all or nearly all organisms which may 
invade the body. The other group of opsonins may be spoken 
of as the specific opsonins. These are not destroyed by heat at 
a temperature under 60° C, and they appear to be produced by 
the body in direct response to specific stimulation. They are 
only capable of opsonizing the special bacteria whose irritation 
has led to their production. Experience shows that when bacteria 
are opsonized by a special opsonin they are equally susceptible 
to leucocytes drawn from widely different sources. For example, 
if bacteria are opsonized by a given blood serum, leucocytes 
from well people, or from people suffering from various diseases, 
and leucocytes taken from some of the other warm-blooded ani- 
mals, all seem to have about the same phagocytic power. On 
the other hand, if different emulsions of bacteria are opsonized 
with different sera it is found that these emulsions are acted upon 
very differently by phagocytes taken from the same source. From 

503 



504 PHYSIOLOGY : 

what has been said, it will be noted that opsonins act solely on 
bacteria and that they have little or no effect upon the phago- 
cytes. Within certain limits, the opsonic index may be used 
both as a means of the diagnosis and of the prognosis of disease. 
It is sometimes a very difficult matter to differentiate between a 
tubercular infection of organs like the kidneys, liver, spleen, etc., 
and a syphilitic infection of these same organs. If the infection 
is tubercular it is almost always true that the opsonic index of 
the patient is low, whereas if the infection is syphilitic his index 
to the Bacillus tuberculosus remains substantially normal. If in 
treating a tubercular case the opsonic index remains compara- 
tively low, it is usually an indication that the patient is passing 
into a chronic tubercular condition, whereas if the opsonic index 
rises to normal, or a little above, it is a very good indication of 
his probable complete recovery. The early workers with the 
opsonic index believed that the only method of increasing the 
index was by using attenuated vaccines of the organism from which 
the patient desired to be protected, but we now know that any- 
thing which promotes good circulation and good digestion, or in 
other words, anything which tends to increase the health of the 
individual, raises the opsonic index. 

A series of experiments conducted at the Pacific College of 
Osteopathy showed that the mechanical stimulation of the liver 
and spleen produced in almost every case a marked increase in 
the opsonic index. This series of experiments seems so conclusive 
along this line that we present the results in this place: 



Nov. 


2 


Nov. 


8 


Nov. 


30 


Dec. 


6 


Dec. 


14 


Dec. 


21 


Jan. 


12 


Jan. 


27 


Mar. 


9 


Mar. 


23 


April 


13 


April 


21 


Since this 



Index . 98 four hours after stimulation 
Index 1 . 1 four hours after stimulation 
Index . 99 four hours after stimulation 
Index 1 . 2 four hours after stimulation 
Index 1 . four hours after stimulation 
Index 1 . 1 four hours after stimulation 



..1.4 
..1.3 
..1.1 
..1.2 
..1.4 
..1.3 



Index . 99 four hours after stimulation ...1.1 

Index . 95 four hours after stimulation . . . 1 . 

Index 1 . 2 four hours after stimulation ...1.2 

Index 1 . four hours after stimulation ...1.2 

Index 1 . 1 four hours after stimulation ...1.4 

Index 1 . four hours after stimulation ...1.3 

work was done experiments have shown that 
moderate exercise produces the same effect. If the exercise is 



GENERAL AND OSTEOPATHIC. 505 

prolonged to the extent of marked fatigue, as is the case after a 
day spent in mountain climbing, there is a period of twenty-four 
lours — a little more or less — during which the opsonic index is 
lowered. This, however, is followed by an increase in the opsonic 
index, and the increase continues for between one and two days. 
The increase in the opsonic index following physical manipulation 
is of short duration and does not appear to continue for more than 
six or eight hours. This may be regarded as an indication that 
osteopathic treatments in cases of acute diseases should be fre- 
quent, and the failure which some physicians have experienced 
in dealing with pneumonia, diphtheria, and other acute diseases 
may be quite as much due to an excessive length of time between 
treatments as to any inefficiency of the system which they practice. 



SECTION XI 



DR. DEASON'S RESEARCH 

WORK 



CHAPTER LIL 

SOME PHYSIOLOGICAL EFFECTS OF VERTE- 
BRAL MOVEMENTS EXPERIMENTALLY 
PRODUCED. 

(The original report was published in full in the Journal of Osteopathy, 

Apr. 1911.) 

J. Deason. 
EXPLANATORY NOTE. 

The following is a report of the research work done by Dr. 
Deason and his assistants. The work for the most part has been 
done in the laboratories of the American School of Osteopathy 
under the general direction of the A. T. Still Research Institute, 
with the exception of the first six series, which were done at the 
author's expense without financial assistance from the Institute. 
The Institute deserves credit for the greater part of the work done 
by other workers who have reported their results in the foregoing 
pages of this part of the book, as it has financially assisted in much 
of the work. 

The different series of work recorded in the following pages 
have been reported in full in The Journal of Osteopathy and 
The Journal of the American Osteopathic Association, and only 
summaries of the work are given here. Some of the series have 
not yet been completed and some pertain to other subjects than 
physiology, therefore the explanation of the missing series. Twenty 
different series of original experimental work have been done 
and the reports of the missing series will be ready for publication 
in the near future. In this work more than six hundred animals 
have been used. The author is greatly indebted to the student 
assistants in the American School of Osteopathy for their help 

509 



510 PHYSIOLOGY I 

in this work, and many deserve credit whose names do not appear 
in connection with the different series as reported. 

SERIES NO. 2. 

In this series of experiments the purpose has been to deter- 
mine the relation of perverted positions and abnormal movements 
of the spine to structural perversions and abnormal movements 
of other parts of the body, and to determine the physiological 
effects resulting from such operations. 

Methods and Technique of Experiments. — Much care 
has been exercised in the selection of animals for these experi- 
ments. Dogs were used, because blood pressure and pulse trac- 
ings can be more readily obtained from these than from smaller 
animals, and no animal was used which had not been kept for a 
sufficient time under normal conditions to determine that it was 
entirely devoid of any abnormalities which might render the 
results valueless. The spine was carefully examined in each case, 
to determine that no bony lesions existed before proceeding with 
the operations. 

Reasons for the above precautions will be better understood 
when the reader is reminded of the fact that the average dog is 
frequently found suffering from constitutional diseases, many 
of which are traceable to spinal lesions, the evidence of which 
statement we hope to bring out at some future time. (See series 
Nos. 4, 9 and 12, which were published later.) 

It is a well-known fact to all workers in physiological research 
that not all animals exhibit average normal functions when oper- 
ated on under anaesthesia. It is necessary, therefore, to experi- 
ment on several animals, and take the average results of those 
which seem to display the most normal reactions under the anaes- 
thetic used. Thus the need of examining the spine of each 
animal used will be readily apparent. The following results have 
been taken from a common average of ten animals operated upon. 

During the operations the animals were kept under complete 
and regular anaesthesia by ether, which was administered by 
means of a tracheal cannula, as it is most satisfactorily regulated 



GENERAL AND OSTEOPATHIC. 511 

in this way. Blood pressure and pulse tracings were taken from 
the carotid artery by the use of a carotid cannula and mercury 
manometer. 

Respiratory tracings were taken from the side arm of a T 
tube, connected on the one hand to the tracheal cannula and on 
the other to a diaphragm tambour, which was made to record on 
the smoked paper of a revolving kymograph simultaneously with 
the blood pressure and pulse tracings mentioned above. An 
electric signal magnet, connected with an inductorum and metro- 
nome, was used to record time and furnish a base line. 

Several normal blood-pressure and respiratory tracings 
were taken from each animal before any tests were applied, to 
determine whether or not the animal was showing normal func- 
tional activities. From five to ten minutes were allowed before 
and after each test for normalization. All results from animals 
whose tracings failed to show normal activities before any tests 
were applied were discarded. 

Preliminary Test to Determine Relation of the Position 
of the Animal to Blood-Pressure Variations. — The caudal 
end of the animal was elevated, thorax remaining on the table, 
to determine blood-pressure variations thus effected. Extreme 
tilting of the body, such as lifting of the caudal end or relative 
lowering of the cephalic end, brings about a marked increase in 
blood pressure, due to the effect of the force of gravity, but in 
the above operation, in which only a part of the animal was lifted, 
the increase in blood pressure was not great, seldom exceeding 
two millimeters of mercury; nor was the result a lasting one, as 
the pressure returned to normal within ten or fifteen seconds 
after replacement of the caudal end upon the table.. The animal 
was then placed in different positions, such as ventrum on operat- 
ing board, dorsum on operating board, and changed from side 
to side, and the blood pressure, pulse and respiratory variations, 
as recorded on the kymograph, were noted. The variations thus 
produced were not great, but were carefully noted for comparative 
purposes. * * * 



512 physiology: 

Functionally Different Spinal Areas. — In the above 
series of experiments we have observed that different areas or 
regions of the spine seemed to produce different functional effects 
from these perverted positions and pressures, but as yet little 
work has been done experimentally, so we urge that it be not 
accepted as conclusive. From the work which has been done it 
would seem safe to say that spinal pressure in many ways simu- 
lates spinal movements produced with fixation, always varying 
the blood pressure, usually the respiration, and frequently affecting 
changes in heart rate and amplitude. 

It is evident that such pressures have wholly different effects 
on blood pressure and rate of heart beat when produced in differ- 
ent areas of the spine, possibly affecting the so-called spinal centers. 

Summary. — While this series of experiments, as has been 
stated above, is only preliminary, and cannot be taken as final, 
enough work has been done to show quite conclusively that cer- 
tain movements of the spine, normal and abnormal, and especially 
those in which fixation was employed, are much more effective 
in producing functional variations than movements or massage 
of other parts of the body. (By fixation we mean the localization 
of movement. One vertebra is fixed, holding it either by the trans- 
verse or spinous process, producing a localization of movement 
at the point fixed.) In the future we hope to offer some suggestions 
on the possible physiological explanation of this, which will be 
based upon experimental evidence. 

That these changes cannot be accounted for by gravity effects 
we think is sufficiently evident from the preliminary tests made, 
and because of the precautions observed to avoid it, as have been 
described. 

That the massage effects could not possibly be responsible 
for these changes is clearly shown by the nature of the effects 
produced in that way. Massage when vigorously applied to any 
part of the body does produce blood pressure, pulse and respiratory 
variations, but in all cases, even when continued for a much longer 
time than the time given to the spinal movements and pres- 
sures, the results are not so great or of so long duration, but quite 



GENEKAL AND OSTEOPATHIC. 513 

conversely returning to normal almost immediately after the 
massage was discontinued. While the blood pressure and res- 
piration are usually slightly increased, the amplitude and rate 
of heart beat are usually unaffected. Massage, in its effect upon 
animals under ansesthesia, therefore, is almost wholly incomparable 
to movements of the spine with fixation. 

The effects of movements of the spine without fixation are 
very similar to passive movements of other parts of the body. 
There is always an increase in blood pressure and respiration, 
but usually no noticeable variations in heart rate and amplitude, 
and the variations are of short duration as compared to move- 
ments of the spine with fixation. Even when hyper-extensions 
and hyper-flexions were employed the changes so effected were 
not at all comparable to changes caused by these movements 
with fixation. 

The effects of movements of the spine with fixation, localized 
movement at some one point, causing an excess of movement or 
partial temporary subluxation, seemed to be most effective in 
the production of functional variations, blood pressure and res- 
piration being affected in all cases, and in many instances the 
heart rate and amplitude of heart. beat being also affected. 

Conclusion. — From the results of this series of experiments 
we have arrived at no hasty conclusion in stating quite definitely 
that of all the different tests which we have described above, 
those movements which affect the spine in such a way as to pro- 
duce conditions comparable to the osteopathic bony lesion are 
the most efficacious in producing abnormal variations in certain 
vital physiological processes, as have been described. 

Granting that this be true, it does not seem unreasonable to 
conjecture that other functions, such as peristalsis, secretion, 
metabolism, etc., would be similarly affected. 



CHAPTER LIII. 
SERIES NO. 3. 

ON THE PATHWAYS FOR THE BULBAR 

RESPIRATORY IMPULSES IN THE 

SPINAL CORD. 

By J. Deason and L. G. Robb. 

The work on this series was done in the Hull Physiological Laboratory, 
University of Chicago, and in the physiological laboratories at the American 
School of Osteopathy. 

Original report was published in the American Journal of Physiology, 
April 1, 1911. 

The experiments summarized in this report were carried out 
at the suggestion of Professor Carlson with the view of testing 
out a possible explanation of the Porter experiment on the spinal 
respiratory pathways. 

On repeating the well-known Porter experiment with a group 
of students in advanced physiology of the central nervous system, 
Professor Carlson found that after hemisection of the cervical cord 
and section of the opposite phrenic nerve in young kittens the 
respiratory impulses do not cross the median line in the cord if 
the animal is in a state of depression at the time of section of the 
phrenic. In such an animal, however, dyspnoea induces crossing 
of the impulses. Dyspnoea also leads to crossing of the impulses 
without previous section of the opposite phrenic nerve. This 
would seem to show that the crossed pathways for the respiratory 
impulses are normally open, and that their use depends upon 
the relative intensity of the impulses discharged from the bulbar 
center. 

The crossing of the respiratory impulses in the Porter experi- 
ment may be: 
5H 



GENERAL AND OSTEOPATHIC. 515 

I. A case of opening up of new reflex paths. The chief 
objections to this explanation are that the crossing takes place 
practically instantaneously on section of the opposite phrenic; 
and that dyspnoea induces the crossing, without the section of 
the opposite phrenic. 

II. The section of the phrenic may raise the excitability of 
the phrenic and the bulbar respiratory centers, and thus increase 
the intensity of the respiratory impulses. In this case the Porter 
experiment becomes simply a special case of the spread of the 
reflex (or automatic) responses pari passu with the increased 
intensity of the stimulus (or the nervous impulses). 

The second hypothesis demands that the phrenic nerves 
contain afferent fibers, whose stimulation increases the intensity 
of the respiratory impulses; and that the crossing should be 
induced by the stimulation of any sensory nerve that causes an 
increase in the intensity of the bulbar respiratory discharges. 



* * * 



RESULTS. 

Confirmation of Porter's Experiment. — In all of our 

experiments it was found that after hemisection of the cord in 
the upper cervical region (second or third segments) the diaphragm 
on the side of hemisection was paralyzed, and provided the ani- 
mals were in good condition, section of the opposite phrenic nerve 
immediately started the respiratory rhythm in the diaphragm on 
the side of the hemisection, followed by a permanent paralysis 
of the diaphragm on the side of the sectioned nerve. 

Porter assumes that "the section of the phrenic nerve inter- 
rupts the ordinary respiratory pathway on the same side, and 
a greater portion, perhaps the whole descending impulse of that 
side passes through the crossed dendrites to the phrenic cells of 
the opposite side." Unless the passage of the bulbar respiratory 
inpulses from their spinal conduction paths to the cells of origin 
of the phrenic motor fibers depends in some way on the normal 
impulses of afferent fibers in the phrenic ; or unless the mere section 
of the phrenic motor fibers by antidromic impulses immediately 



516 physiology: 

blocks the passage from the spinal conduction paths to the phrenic 
cells, there is no reason for assuming such an "overflow" of the 
impulses to the opposite side. 

The crossing of the bulbar respiratory impulses at the level 
of the phrenic nuclei after hemisection of the spinal cord can be 
induced by traction on the phrenic nerve of the intact side of 
the cord. The traction need not be great enough to block the 
impulses in the nerve. In fact, if it is properly adjusted, a uni- 
form respiratory rhythm is induced in both sides of the diaphragm. 

Stimulation of the sciatic nerve induces crossing of the res- 
piratory impulses and an equal contraction of each lateral half 
of the diaphragm, which may continue for ten minutes after the 
cessation of the stimulation. 

SUMMARY AND CONCLUSIONS. 

1. The phrenic nerves contain afferent fibers, the stimulation 
of which augments the intensity and the rate of the bulbar res- 
piratory impulses. The effects of stimulation of these fibers 
on the respiratory center outlasts for varying lengths of time the 
period of stimulation. 

2. After hemisection of the spinal cord between the medulla 
and the phrenic nuclei and consequent paralysis of the diaphragm 
on the hemisected side, the bulbar respiratory impulses will cross 
from the intact to the hemisected side of the spinal cord on stimu- 
lation of the sciatic nerve; on traction or mechanical stimulation 
of the phrenic nerve on the intact side of the cord; in dyspnoea; 
as well as on section of the phrenic nerve on the intact side. 
These various conditions induce increased intensity of the 
bulbar respiratory impulses. The immediate crossing of the 
bulbar respiratory impulses on section of the phrenic nerve 
after previous hemisection of the opposite side of the cervical 
cord seems therefore to be a case of the spread of reflex (or auto- 
matic) responses pari passu with the increased intensity of the 
nervous impulses. But since in the Porter experiment the crossing 
of the impulses appears to be permanent, additional factors are 
probably involved. 






CHAPTER LIV. 
SERIES NO. 4. 

RELATION OF SPINAL LESIONS TO CARBO- 
HYDRATE METABOLISM. 

J. Deason, D. O. 

A Report on the Fourth Series of Mammalian Experiments, from the 
Physiological Laboratories of the American School of Osteopathy; published 
in the Journal of the American Osteopathic Association, June, 1911. 

The original purpose of this series of experiments was to de- 
termine the relation of the spinal bony lesion to carbohydrate 
metabolism. Later, however, several other problems have arisen, 
such as the relation of these lesions to nutrition, normal functions 
of the stomach and intestines, gastro-intestinal infection, etc.; 
therefore some preliminary notes will be offered on these subjects 
in the summary of this article. 

LITERATURE. 

In reviewing the literature of the experimental work which 
has been done on the relation of the pancreas and other organs to 
carbohydrate metabolism, we find the following to report: It 
would seem that here as well as in most other functional disturb- 
ances that not only one, but in many cases, several structures are 
involved, and considering, as all physiological experimenters now 
well understand, the fact that many, or possibly all, organs 

OF THE BODY BEAR A CERTAIN ESSENTIAL FUNCTIONAL RELATION- 
SHIP WITH EACH OTHER, WE CAN SEE HOW A DISTURBANCE OF THE 
FUNCTION OF ONE STRUCTURE MIGHT EASILY AFFECT THE FUNC- 
TIONAL ACTIVITY OF ANOTHER. 

517 



518 physiology: 

That either direct or indirect interference with the nerve 
supply to the pancreas and other related structures plays an 
important part in the production of glycosuria, we offer the fol- 
lowing evidence from the literature: 

Effects of Total Extirpation of the Pancreas. — Pfluger 
believes that the fact that glycosuria which follows the extirpation 
of the salivary glands and the thyroid glands is generally attrib- 
uted to the nervous phenomena would warrant a careful considera- 
tion of nervous elements in pancreatic glycosuria. After a con- 
sideration of the cases of partial extirpation of the pancreas cited 
in the literature, Pfluger concludes that in those cases where 
glycosuria occurred the cause lay in the nervous disturbances. 
All, or practically all, of the investigators agree that after partial 
extirpation of the pancreas glycosuria is exceptional rather than 
general. Pfluger attributes the results of J. Thiraloix, who holds 
that there is invariably glycosuria resulting after partial extirpa- 
tion, to poor technique in the removal of the pancreas and ac- 
companying injury or violent stimulation of the nerves. Like- 
wise, in H. Luthjes's experiments, Pfluger places the source of gly- 
cosuria in the white gangrene resulting from the cauterizing and 
which is undoubtedly a violent irritant to the nerves. Pfluger's 
own colleague Wetzee, never found glycosuria to result after 
partial extirpation of the pancreas in dogs except in the case of 
one female which was suffering from acute peritonitis. 

Pawlow has shown that the pancreas is innervated by the 
vagus. E. Kulz claims that stimulation of the central end of 
the cut vagus leads to glycosuria. E. Cavazzani's work tends to 
show that stimulation of the celiac plexus causes sugar synthesis 
in the liver. The number of ways in which nerve stimulation 
may affect the metabolism of the carbohydrates is many. Claude 
Bernard maintains that the puncture of the floor of the fourth 
ventricle in the rabbit is followed by a transitory form of diabetes, 
the so-called Pique diabetes. This is known as the diabetic area. 
Pfluger says: "It is hardly to be doubted that there is a compli- 
cated nervous mechanism regulating the sugar metabolism much 
in the same way as the heart is regulated by a complex nervous 



GENERAL AND OSTEOPATHIC. 519 

system." Minkowski finds that in dogs and other mammals 
complete extirpation leads to the severest forms of diabetes melli- 
tus. In other animals he found the same to be true, which has 
been verified by nearly all workers on this problem. 

Pfluger, in experimenting on frogs, produced diabetes after 
removal of the pancreas in all but one case. He says that failure 
to obtain glycosuria after total extirpation is due to the blood 
supply of the liver being very intimately connected with the 
pancreas and hence it is difficult to remove all without injuring 
the liver. If such a relation between the liver and the pancreas 
exists (and we find nothing in the literature which questions it) 
these two organs as well as the stomach and duodenum should bear 
a certain functional relationship with one another. Marius got 
diabetes in twelve frogs out of nineteen experimented upon. 
Gaupt also believes that the negative glycosuria in frogs upon 
removal of the pancreas, as reported by Minkowski, is due to its 
intimate connection with the liver. 

Pfluger in one paper advances the theory that two antago- 
nistic powers regulate the sugar content of the urine. One is 
the function of the nervous system and has its center in the medulla. 
This power may cause a rise in the sugar content of the urine. 
The storing of glycogen in the liver depends partly upon this 
center. From all parts of the organism centripetal nerves pass 
to this center so as to regulate the needs of the organ. The force 
is a chemical or anti-diabetic force of a substance secreted in the 
pancreas. By some unknown force it hinders the formation of 
sugar in the blood. Bernard and Eckhard have determined 
that the sugar center for metabolism lies in the medulla and works 
through the splanchnic area on the production of sugar from 
glycogen. As long as any part of the pancreas is alive it must 
have a central nervous connection b}^ means of the fine network 
of nerves along the blood vessels supplying blood to the pancreas. 

There seems to be sufficient reason for accepting this nervous 
mechanism by way of the splanchnics, but whether they are secre- 
tory, trophic, regulatory, or perform their function by regulating 
the blood supply has not been determined. Pfluger argues that 



520 PHYSIOLOGY : 

the pancreas has a direct connection with the sugar center and 
consequently with the liver and duodenum. Evidently the 
glandular substance must play some important part in the sugar 
metabolism, as diabetes results immediately on the removal of 
the last small part which previously had prevented the diabetes. 
In this way the excessive formation of sugar is counteracted by 
the action of the secretion of the pancreas to form an anti-diabetic 
ferment. 

Partial extirpation, that is, from the head or tail of the gland, 
leaving from one-third to one-fifth of the organ, gives the fore- 
going results, but the quantity of gland remaining is not as neces- 
sary as its state of nutrition, blood supply, and innervation. 
(This fact, taken from the general physiological literature, is 
of great osteopathic importance. The function of any glandular 
structure varies directly, as its blood and nerve supply, a part of 
the gland itself may be removed without in many cases any 
marked perversion of functions, but nerve and blood supply are 
of greater importance.) Minkowski found glycosuria to be very 
slight in one case where he had left a part of the gland the size of 
a pea. In this case, on feeding protein the sugar disappeared 
in the urine but reappeared on carbohydrate diet. Minkowski and 
Sandmeyer have observed cases of incomplete extirpation in which 
a slight glycosuria appeared which gradually reinforced itself 
and grew to a severe case of diabetes. This evolution comes 
about from a degeneration of the glandular elements after atrophy 
of the fragments of the gland remaining from the partial extirpa- 
tion. According to Minkowski partial extirpation gives three 
results, viz.: First, absence of diabetes; second, diabetes of a 
light form; third, a light form of diabetes which gradually be- 
comes severe. It would seem, and in fact it is stated by 

SOME OF THE MOST EXPERIENCED WORKERS, THAT IT IS THE INTER- 
FERENCE WITH THE BLOOD AND NERVE SUPPLY AND NOT THE LACK 
OF GLANDULAR TISSUE WHICH CAUSES THE GLYCOSURIA IN PARTIAL 
EXTIRPATION. 

Relation of Pancreas and Liver. — According to Cheveau 
and Kaufman, the pancreas is coupled with the liver in relation 



GENERAL AND OSTEOPATHIC. 521 

to glycogen formation. The formation of sugar from glycogen 
is increased after extirpation of the pancreas, and the amount of 
sugar used by the body remains the same. The sugar content 
of the blood is the same before or after the animals have been 
rendered diabetic. Section of the cord below the bulb, whether 
alone or combined with extirpation of the pancreas, causes diabetes 
and, according to Cheveau and Kaufman, there are two centers 
in the bulb influencing the formation of sugar from glycogen. 
These two centers are acted on by the internal secretion of the 
pancreas in an opposite way. The inhibitory center is excited 
and the excitatory center is inhibited. The extirpation of the 
pancreas destroys the action of the inhibitory center and acti- 
vates the excitatory center, thus causing the formation of sugar 
from the glycogen. 

The internal secretion exercises a powerful retarding action 
on the disintegration of the tissues. Over-production of sugar 
from the liver is the cause of pancreatic diabetes. First, from a 
disturbance of the nervous mechanism regulating the hepatic 
glucose formation; second, by direct action on the liver (suppres- 
sion or a moderating action which produces the internal secretion 
of the pancreas, which acts directly on the hepatic-glucose forma- 
tion) ; and third, from histological disintegration, a larger amount 
of that material passes into circulation which is apt to form sugar 
in passing through the liver, i. e., a suppression of the moderating 
action of the pancreas on that substance. 

Cutting the vagi and splanchnics has been found by Von 
Graefe and V. Henson to produce temporary glycosuria. The 
same kind of glysocuria is obtained by cutting the lower cervical 
ganglion. In four or five hours a maximum diabetes is reached. 
Traces may be found for even twenty-four hours. Eckhard ob- 
tained slight glycosuria upon cutting the upper chest ganglion of a 
sympathetic nerve. Dr. Emil Canazzani has done some inter- 
esting experiments upon the celiac plexus. He stimulated the 
nerves to the liver, electrically, and obtained a decrease in the 
amount of glycogen in a few moments and an inverse in sugar 
content. Two dogs were experimented upon, the stimulation 



522 physiology: 

being kept up for from five to fifteen minutes. In the first dog 
the glycogen was 1.67%, and after stimulation was .77%. The 
other dog showed 3.94% before, and 2.30% after stimulation. 
How does this affect the formation of antibodies in the pancreas? 

If the vagus is stimulated in the neck the stomach and 
oesophagus contract while the peristalsis of the intestine is ap- 
parently not affected, yet we know that the vagus exerts a power 
over the intestines. Many have stimulated and obtained no 
secretion of the pancreas or stomach, yet Pawlow has conclusively 
proven that. So far it has been contended that the plexus of the 
duodenum controls the secretion of antibodies in the pancreas. 

Now it is to be proved that the duodenum does not have an 
internal secretion which helps to form the antibodies. Hedon 
grafted a piece of pancreas into a dog. This piece was connected 
with the peritoneum through nerves and blood vessels, then the 
entire pancreas was removed. Later the connection with the 
mesenteric nerves and blood vessels was cut and no diabetes 
resulted, hence the duodenum cannot form antibodies and does 
not influence the pancreas excepting when there is a nervous 
connection. This is of no immediate value to us in presenting 
the argument set forth in this article other than to show the nervous 
relationship existing between the duodenum and pancreas. 

Transplantation. — Hedon transplanted part of the pan- 
creas under the skin and then removed the remaining pancreas. 
In this case no diabetes resulted, but when the grafted portion 
was removed diabetes immediately became evident and sugar 
was found in the urine. He says that few cases in which the 
above is not the result can be attributed to the outgrowth of the 
grafted pancreas upon the wall of the abdomen and the failure 
to remove this outgrowth. Sbolew, Minkowski, Thiraloix, Pfluger, 
and others, by similar experiments have partially confirmed these 
results. 

Feeding or Injecting of Pancreatic Extract. — If the 
pancreas produces a substance which aids sugar metabolism it 
would seem possible and necessary, in order to prove this secre- 
tion, to obtain from the extirpated pancreas a substance which 



GENERAL AND OSTEOPATHIC. 523 

upon injection into a diabetic animal would prevent the excre- 
tion of glucose in the urine. In 260 cases performed by Hedon 
there have been few results on injection of this pancreatic extract. 
Capparelli, however, with the same proceedure, found that the 
sugar secretion was lessened in three hours and in most cases it 
completely disappeared. But Pfluger contends that in his ex- 
periments there seems to be some doubt as to whether he had 
i removed all of the pancreas. Experiments by many prove that 
feeding the pancreas of cattle increases the sugar from three to 
four times the normal amount. 

Other Methods of Causing Glycosuria. — Minkowski 
says that sugar elimination may be caused first by eating much 
sugar (alimentary glycosuria), that is, flooding the organism with 
it; second, by rapid changing of glycogen into sugar by the liver, 
causing an increase in the blood and consequently sugar in the 
urine; and third, by the administration of certain drugs. In 
pancreatic extirpation the oxidation of sugar is disturbed, while 
the drug causes sugar elimination without disturbing oxidation 
of the sugar. It causes the kidneys to take the sugar from the 
blood and secrete it, thus causing the percentage of sugar in the 
blood to fall below normal. It is thus shown that increased elimi- 
nation of sugar in the urine can be caused in other ways than by 
disturbance of the function of the pancreas. It would seem from 
this that any interference with the innervation or nerve supply 
to the pancreas, liver, or duodenum might effect at least a low 
percentage of glycosuria. 

Proofs of Internal Secretion. — As long as there is no other 
proof at hand than that which has been advanced so far, the 
theory of internal secretion must stand. Hedon has. taken the 
sterilized extract of pancreas and injected it in large doses intra- 
peritoneally and intravenously, without checking the diabetes. 
He found that the injection of water or glycerin extract of pan- 
creas intraperitoneally always produced a large amount of pus, 
even though the greatest care was exercised. If the extract 
was filtered through a medicated candle, hard knots appeared 
in place of the abscess and these were gradually absorbed. Hedon 



524 physiology: 

thinks the candle removes the .protein and enzymes. After this 
nitration large amounts may be injected intravenously without 
killing the animal. Pfluger tries to disprove the theory of Min- 
kowski that pancreatotomy retains the toxins of the liver, by 
transfusion of blood from a diabetic animal to a healthy one with- 
out producing glycosuria in the healthy dog. 

Chemical Stimulation. — Diabetes may be produced by 
chemical means. Certain substances such as phloridzin and 
uranium salts, are capable of producing a severe glycosuria, which 
has been thought to be due to the detrimental action of these 
substances on the kidney cells. Coincident with this type of 
glycosuria there is a diminished sugar content in the blood. Var- 
ious other substances, such as carbon dioxide, adrenalin, ether, 
chloroform, morphine, curare, veratria, pyrogallol, salicylatis, 
pilocarpin, amyl nitrate, and potassium cyanide, possess the 
property of inducing glycosuria, and as far as has been investi- 
gated, according to Underhill, an accompanying hypoglycemia 
has been noted. Obviously, he says this type conforms more 
closely to the true diabetes. Harter has shown that glycosuria 
is usually readily produced by painting the pancreas with piper- 
idin or by intraperitoneal injection. At times this sugar elimina- 
tion is very marked and may persist for several hours. Again 
the glycosuria is very slight or may be entirely lacking, even though 
large doses of the drug have been given. Piperidin was selected 
by Harter as he thought it a typical representative of a number 
of drugs which produced glycosuria. In the case of piperidin 
glycosuria as studied by Harter, two attempts were made to de- 
termine whether it was accompanied by hyperglycemia. In neither 
of these experiments was the sugar content of the blood changed, 
and the suggestion was made that the renal factor is associated 
with this form of glycosuria. These experiments have been re- 
peated by Underhill and the influence of piperidin applied to the 
pancreas with the following results: In three experiments by 
painting the pancreas with 5 c. c. of 4% piperidin he got only an 
average increase of .07% of sugar in the blood. This appears 
contrary to Harter's results mentioned above, but not so much 



GENERAL AND OSTEOPATHIC 525 

of an increase when we recall that probably .04% of this amount 
obtained might have been due only to the anesthesia, leaving 
possibly .03% actually produced by the painting of the piperidin. 
These results also present variations of as much as .09%, and no 
two of them check closer than .03%, so that the inaccuracy of 
such results is plainly evident. In reviewing the tables of ex- 
periments performed by Underbill, Scott, and others, we find that 
in many cases the glycosuria is lacking. This may be explained 
by the fact that small or insufficient doses of the drug were given, 
and hence the increase in sugar content of the blood was not suffic- 
ient to cause elimination by the kidneys. Hedon, Gley, and 
Thiraloix have caused a profound degeneration and atrophy of 
the pancreas by injection of various substances without causing 
a trace of diabetes. Advocates of the internal-secretion theory 
maintain that under the foregoing conditions small portions of 
the pancreas probably escaped Regeneration. On the other hand, 
adherents to the nervous theory fail to conceive how microscopic 
remnants could so thoroughly regulate sugar metabolism. 

Relations of the Islets of Langerhans and the Zymo- 
genous Tubules in the Pancreas. — After inanition, in some 
animals at least, it has been shown by Statkewitsch that there 
is a material increase in islet tissue. This statement has been 
confirmed by Vincent and Thompson, and also by Dale. There 
are rows of epithelial cells separated by very large expanded cap- 
illaries, as in the thyroids. They thus present a very large sur- 
face to the blood stream. Between these rows of cells can be differ- 
entiated at times very fine granular substances which are after- 
wards extruded into the lumen. 

From the above it will be seen that much work has been 
done in an attempt to determine the various causes of glycosuria 
and hyperglycemia. The results of these workers are so much 
at variance that it is indeed difficult to arrive at any definite con- 
clusion. That the nervous system has at least a regulatory 
influence upon carbohydrate metabolism seems to be conclusively 
settled. That the blood supply to the pancreas also plays an 
important part seems quite probable in that it effects a greater 



526 physiology: 

or lesser functional activity by the quantity supplied, and by 
association of various organs through internal secretions. That 
the pancreas produces an internal secretion which is essential 
to carbohydrate metabolism has also been established. 

RELATIONS OF THORACIC BONY LESIONS TO CARBO- 
HYDRATE METABOLISM. 

It has been our purpose in this series of experiments to de- 
termine the relation of thoracic bony lesions on similar functions. 
Drs. McConnell and Farmer have done work on the relation of 
spinal lesions to functional disorders. They have found that 
spinal lesions in some cases, at least, are accompanied by glycosuria 
but the greater part of their work has been along other lines. 
So far as we know, nothing has been done with this one purpose 
in view. 

From the osteopathic texts we find the following: "1 have 
found variations from the normal generally beginning with the 
ninth dorsal. I carefully examine and adjust every section of 
spine to the sacrum and coccyx, also the eleventh and twelfth 
ribs on both sides. These variations act powerfully on the ex- 
cretory system and excite and irritate the solar plexus, which 
gives off branches to the abdominal -excretory system." (P. 401, 
Osteopathy — Research and Practice, by Dr. A. T. Still.) " Almost 
invariably there will be found a posterior dorso-lumbar curvature 
wherein the spinal-column tissues are much contracted. This 
condition probably involves the sympathetics (vasomotor and 
trophic), to the pancreas, liver and intestines." (Practice of 
Osteopathy, McConnell and Teall.) 

It would seem logical that if the bony lesion produces func- 
tional errors in the cord or splanchnic fibers, either or both, that 
these disturbances should interfere with the nervous mechanism 
which, as has been pointed out above, regulates certain functional 
activities governing carbohydrate metabolism, errors of which 
bring about certain functional disturbances, such as glycosuria 
and hypoglycemia. That^spinal bony lesions produce marked 



GENERAL AND OSTEOPATHIC. 527 

variations in blood pressure has already been demonstrated in 
our mammalian experiments, Series No. 2. (See page 510.) 

The results of continued lesions on blood pressure have not 
as yet been determined by experiment, but judging from the 
results of the work that has been done we find that lesion in, or 
pressure on, the mid-dorsal produces an increase in blood pressure 
by vaso-constriction. Now we know that over-stimulation results 
finally in inhibition, which would mean vaso-dilation and an 
increase in blood supply to the parts innervated by the nerves 
from this region of the spine. This would mean a greater amount 
of blood than the veins could normally carry away, and therefore 
a congestion of the parts which in turn would mean a temporary 
increase, followed by a decrease, in function. We know that 
the functional activity of most secreting glands varies directly 
with their blood supply. The ability of the gland to produce 
internal secretion normal in quantity and quality should also be 
affected by any interference with its nerve or blood supply. There- 
fore, considering that the pancreas produces an internal 
secretion which performs an important function on carbohydrate 
metabolism, this would be materially affected by the spinal bony 
lesion if our reasoning is correct. 

Experimental Methods Employed. — Many things were 
to be considered in the study of functional effects. The normali- 
zation or the selection of normal animals is always first, for obvious 
reasons. Dogs were the animals used, because they may be more 
easily managed and will furnish sufficient urine for examination. 
Healthy dogs of medium age were used, as these are more likely 
to be normal. Each dog was kept from one to four weeks before 
being caged. It was usually necessary to feed the dogs regularly 
for a time to get them in good condition and accustomed to the 
new environment. If, after this preliminary test, the dogs seemed 
normal they were then placed in a cage and their physical condi- 
tion was more carefully studied. 

This cage, built of iron bars, was thirty inches wide, thirty 
high, and eighty long. Each cage was divided into two com- 
partments separated by a sheet-iron partition, and stood twelve 



528 physiology: 

inches from the floor. The floor of the cage consisted of heavy 
screen wire resting upon iron bars, which allowed the urine to 
pass through and be immediately separated from the feces or 
other material from the dog's body. Beneath the screen floor 
a zinc pan was suspended which served to collect the urine and 
drain it into another container. The door of the cage consisted 
of one entire end hinged in such a way that it might be removed. 
All parts of the cage were made so that they might be removed 
for cleaning and sterilizing. These cages were painted, that 
they might be more easily cleaned and to prevent iron-rust con- 
tamination in the feces and other material to be examined. The 
cages were washed clean with hot water and brush, and sterilized 
with boiling water and steam twice daily. The containers used 
for collection of urine were cleaned and sterilized at the same 
time. Six such cages were used, accomodating twelve animals 
at a time. 

Care of the Animals. — After the animals selected had 
been kept long enough to determine that they were in good physical 
condition they were given a soap bath in warm water and a thor- 
ough scrubbing with a brush, followed by a cold shower, and 
placed in the cages for normalization. Samples of urine were 
then taken twice daily and qualitative and quantitative analyses 
made. 

Normalization of Dogs. — After being thoroughly washed, 
each dog was carefully weighed (a special pair of scales being used 
which were sensitive to 25 grams), and placed in a separate cage 
and left for from eight to twelve hours, after which time the nature 
and consistency of the feces were noted and the urine tested. The 
dog was fed and watered and given exercise by allowing it to run 
about on the campus, or when the weather was too bad they were 
allowed to run free in the room. The cages were again cleaned 
and sterilized with boiling water and steam and the feet of the 
dogs washed before returning to the cage. Once or twice each 
week the dog received a soap scrubbing and shower bath. A 
regular mixed diet was given twice daily, the amount of food 
and water taken each day being noted. If the dog, after being 



! 



GENERAL AND OSTEOPATHIC. 529 

kept under such circumstances for a period of from two to four 
weeks, showed no abnormal symptoms and its urine was free 
from sugar and was otherwise normal, and if the dog gradually 
increased or remained constant in weight (dogs will usually show 
a constant increase in weight when kept under such conditions), 
it was considered normal and ready to be tested. Before lesioning 
each animal was etherized, usually two or three times, to deter- 
mine the effects of the anesthetic on the functional activities of 
the dog, and particularly its relation to production of sugar in 
the urine. (Some animals show a slight glycosuria, from .03% 
to .1% after administration of ether.) The animal was then left 
for a few days longer and, if no abnormal symptoms deveolped, 
was lesioned. 

Methods of Producing Bony Lesions. — The dogs, after 
normalization, were placed under complete ether anesthesia, 
which was maintained until. the lesion was produced. Traction 
to the spine was first applied by pulling upon the caudal end 
while the anterior part of the body was held. After stretching, 
the lesion in the thoracic region (mid- and lower dorsal) was 
produced by rotation with fixation, one individual holding the 
vertebra by pressure on its spinous or transverse process while 
another rotated the caudal end of the animal. As soon as a 
marked subluxation could be palpated the animal was released 
and placed in a normal position and the vertebrae again palpated. 
It is no easy task to produce a permanent bony lesion in a healthy 
dog, as they often adjust themselves while coming out of the 
anesthesia, or within a few hours after the operation. Often the 
same lesion must be produced from three to six times before it 
remains, and in a few dogs we were never sure that we got a per- 
manent bony lesion. (After more experience and study the work 
of lesioning in our later series became much easier.) This fact 
in itself, however, is no argument against the existence of the 
bony lesion in man, because of the anatomical differences between 
the dog's spine and the human. The dog's spine is so different 
in many respects that it makes necessary a careful study of its 
particular anatomy before any tests may be successfully tried. 



530 PHYSIOLOGY ! 

Care of Dogs after Lesioning. — After lesioning, the ani- 
mals were placed in their cages and watched until they had re- 
\ covered from the anesthesia. The care after lesioning was the 
same as given above under " Normalization, " except that they 
were not exercised for a day or two after the lesion was produced. 
This was done to prevent accidental correction of the lesion from 
vigorous exercise. Two rooms were used for the dogs, both of 
which were supplied with steam heat which could be well regu- 
lated, hot and cold water, and steam for sterilization and good 
ventilation. The floors were scrubbed every day and everything 
kept in a sanitary condition, to maintain good environmental 
conditions. One room was kept for the cages, the other for a 
" playroom" where the animals could take regular exercise. Dur- 
ing spare time twenty students were kept busy for a period of 
thirteen months caring for these animals, analyzing the urine, etc. 
Only two dogs were given to one student at a time. A daily 
record of the general condition of every animal was kept in a 
ledger as follows : Weight, diet, amount of food and drink, nature 
of feces, etc., to which was added the urinary findings. 

Post-Mortem Examination. — After a permanent lesion 
had been produced the dogs were kept from two weeks to seven 
months under the above described condition. After a good 
record had been obtained the dogs were killed by the use of chloro- 
form and placed immediately upon the operating table, ventrum 
down. The skin was laid open the entire length of the spine and 
laid back. The superficial appearance of muscles and fascia 
was carefully inspected in the presence of other members of the 
faculty. The entire spine was then removed, the ribs being 
clipped off two or three inches from the spine, which was then 
examined as to its general contour, curvatures, specific subluxa- 
tion, etc. In some cases deep dissections were made, but usually 
it was placed immediately into fixing solution and given to a 
pathologist, together with specimens of the viscera for patho- 
logical examination. This part of the work has not as yet been 
completed and therefore we cannot report on the findings at 
this time. 



GENERAL AND OSTEOPATHIC. 531 

Results. — It has been suggested that such lesions as we 
claim to produce experimentally could either not be produced and 
made to remain as permanent subluxations, or they would be 
complete luxations, in which case there would be trauma to the 
cord and the effects would be produced in this way. That per- 
manent subluxations can be produced experimentally on animals 
has been conclusively proven by the work of Drs. McConnell 
and Farmer and verified by the results of this series of experiments. 
That these lesions were not luxations which could cause any 
trauma to the cord is evident from the many post-mortem exami- 
nations which have been made by Drs. McConnell and Farmer 
and by the work reported in this article. That the subluxations 
which we have produced do not produce their effects by pressure 
or trauma to the cord is evidenced by the fact that none of our 
lesioned animals has ever developed the slightest paralysis or 
other symptoms of trauma -to the cord. 

SUMMARY AND CONCLUSION. 

The above results have been given very briefly, for space 
would not permit a complete description of the physical condition 
and urinary findings. Thirty-three animals were used in all, 
but only fifteen of these could be sufficiently well normalized 
to be used for lesioning. It is obvious that control work in such 
a series of experiments is absolutely necessary, or the results 
would be valueless. In order that we might know that the effects 
obtained were not due to the diet given or to any environmental 
condition, only six of the animals were kept lesioned at one time, 
the others remaining normal. The normal animals therefore 
furnished controls against the lesioned animals. ' All of these 
animals were controlled against themselves, " normalized, " and 
also controlled against other animals before and after lesioning. 
This insured that the results obtained were not due to accidental 
causes. There were never any functional disturbances resulting 
from the diet given or from the conditions under which these 
animals were kept. 



532 PHYSIOLOGY : 

Each of the fifteen animals which were normalized, out of the 
thirty-three used, showed some functional disturbances from the 
lesions produced. These disturbances varied from a slight abnor- 
mality in urinary findings, which probably would never have 
caused any serious trouble, to conditions sufficiently severe in 
nature to cause death. (Animal No. 4.) 

Glycosuria appeared or was increased in every animal lesioned, 
varying in amount from a trace to 5%. That this condition was 
a permanent functional disturbance is shown by the fact that 
in animals kept from three to seven months after lesioning the 
percentage of sugar either remained constant or increased in 
amount during the entire time, except in animals in which the 
lesions were accidentally corrected. 

Either constipation or diarrhea followed lesioning in eight 
out of fifteen dogs used. In some cases this was only mild, but 
in four animals, Nos. 4, 9, 10, and 11, this was of a severe type. 
Gastro-intestinal disorders resulting in vomiting, etc., occurred 
in five animals. 

A severe vaginal infection appeared in one animal (No. 10), 
which cleared up when the lesion was corrected. A few of the 
animals which would not normalize were dissected to determine 
if a bony lesion could be found that might explain the cause. 
In most cases either specific subluxations or curvatures were 
found. This part of the work was left to be investigated by the 
pathologist. 

In conclusion it would seem safe to say from the above re- 
sults that we believe that spinal bony lesions, particularly those 
in the mid- and lower dorsal, bear some relation to carbohydrate 
metabolism and the occurrence of sugar in the urine; that there 
seems to be some relation between these lesions and constipation 
and diarrhea and possibly stomach and intestinal disorders. It 
would also seem possible that these lesions might in some way 
predispose to infection. We are undecided as to the effect of 
these (mid- and lower dorsal) lesions on nutrition. In most 
cases, for the first few weeks, at least, there was no loss of weight 
following the lesion, but in nearly all cases after being kept for 



GENERAL AND OSTEOPATHIC. 533 

from two to four months, in some instances in less time, the ani- 
mal began to show trophic disturbances and loss in weight; but 
it would be unsafe to say with any definiteness that the loss of 
weight was effected by the lesion produced. 

We have often been asked if we attempted any correction 
of these lesions that caused functional disturbances. We have 
not tried this, as it was our purpose only to determine whether 
such lesions would produce functional disturbances in perfectly 
normal animals — and we believe they do. The results of this 
series have been briefly but definitely stated just as they were 
found. Physicians who read this report will be well able to inter- 
pret the results in each case, therefore no lengthy conclusion is 
necessary. 






CHAPTER LV. 
SERIES NO. 5. 

SOME SPINAL SYMPATHETIC REFLEXES. 

L. G. Robb, D. O. 

(From the Research Department of Physiology, American School of 

Osteopathy.) 

It was our purpose in this series of experiments to try to 
gather some information on certain physiological questions which 
seem to bear some relationship to certain osteopathic principles. 
The work is a continuation of our first series of mammalian experi- 
ments, which we hope to present more fully at some future time. 

Problems. — Does the sympathetic system react to the 
stimulation of all typical spinal and cranial sensory nerves? Is 
there any special reaction for the stimulation of these nerves? 
If so, what is this reaction and what conditions may influence 
it; if not, where may we expect the reaction? 

Results. — In a few cases stimulation of the sciatic with the 
splanchnics intact either failed to stop or initiated a peristalsis. 
In these cases distinct bony lesions were noted in the dorsal region 
of the spine. Some dogs having lesions in this area did not react 
thus, but gave the normal inhibition. After section of one splanch- 
nic in dogs that reacted normally the results were variable. In 
most cases a feeble peristalsis of the stomach would start at vary- 
ing intervals, to be lost before reaching the pylorus; in others 
a distinct peristalsis would be started which continued for a short 
time after removal of the stimulus. In normal dogs with both 
splanchnics cut, stimulation of a sensory (sciatic or cord of brachial) 
nerve caused peristalsis in the stomach (reflex over the vagus) 
which was generally continued on to the duodenum. Stimulation 

534 



GENERAL AND OSTEOPATHIC. 535 

of the intact vagus with a weak induction current for 30 to 60 
seconds decreased the latency period and increased the strength 
of the peristaltic movement reflexly excited, which previously 
was impossible to elicit or had been very weak. The latency 
period, character and duration after removal of the stimulus, 
showed great individual variation. I observed in three cases 
with the splanchnics intact what I took to be a reverse peristalsis. 
The contractions were vigorous, beginning at the pylorus and 
progressing rapidly to the cardia. 

Conclusion. — 1. Stimulation of the central end of a spinal 
or cranial sensory nerve equals in effect stimulation of the periph- 
eral end of some sympathetic nerve or nerves. 

2. The visceral (sympathetic sensory) afferent fibers appear 
to be particularly efficient for vasomotor reflexes. 

3. There are special (habit) reactions for the stimulation 
of some afferent nerves, but this specificity may be changed to a 
general reaction by anything that will decrease or interrupt the 
irritability or conductivity of the efferent element. 

4. Internal environment may open up other so-called specific 
reflex paths. 

5. Anything which increases the irritability and conductivity 
of the efferent element increases its reflex response. This increase 
may be both qualitative and quantitative. 

6. Normally the general reflexes have a tendency to bring 
about passive (inhibitory) reactions. 

7. Other conditions being equal, there is a tendency for 
homonymously related segments to respond. 






CHAPTER LVI. 
SERIES NO. 7. 

OSTEOPATHIC STIMULATION AND 
INHIBITION. 

H. L. Collins and Chas. R. Eitel. 
(Published in the Journal of A. O. A., July. 1912.) 

This work was suggested by Dr. Deason for the purpose of 
determining whether the so-called osteopathic stimulation and 
inhibition effects, as claimed by some physicians, could be demon- 
strated upon animals and also for the purpose of doing some 
control work on mammalian Series No. 2 done last year by Drs. 
Deason and Robb. 

It has long been claimed by members of the profession that 
osteopathic manipulation, such as vigorous movements of one or 
more of the spinal segments either alone or with deep manipu- 
lation of muscles are stimulatory in nature, meaning that such 
changes as increase in heart beat, both rate and amplitude; in- 
crease in blood pressure, increase in body temperature, and, 
in fact, an increase in many or possibly all functional activities 
controlled by nerves from these segments may be effected, and 
that its effects be directed to certain body organs. The theory 
claims, also, that by deep and well-regulated pressure applied 
to the spine a diametrically opposite effect, or inhibition of the 
functions of those structures supplied by nerves from the segments 
pressed upon, may be produced. 

On the other hand, there are those physicians who claim that 
neither stimulation nor inhibition results from osteopathic treat- 
ment, but that it is only a normalization; that is, if an osteopathic 
lesion of any type, bony or otherwise, exists which is responsible 
536 



GENERAL AND OSTEOPATHIC. 537 

for perversion of function, the correction of this lesion will result 
in a normalization of the function. Thus, if the lesion has caused 
a decreased functional activity of a certain organ, this functional 
activity will be raised to or toward the normal after the lesion 
is adjusted; and if the functional activity is increased by reason 
of the lesion, it will be reduced to normal upon readjustment of 
the structural condition. 

By the above definition we do not refer to the question of 
osteopathic inhibition (pressure) applied over areas of the body 
rather than spinal regions. That pressure applied over certain 
nerve trunks and visceral structures will result in the reduction 
of pain and other functional disturbances has been demonstrated 
by clinical experiences of many osteopathic practitioners. 

It has been sufficiently demonstrated (Series Nos. 1 and 2) 
that the pressure results were not due to massage, but to pressure 
stimulation alone; for although in cutaneous and deep muscular- 
pressure stimulation slight variations in blood pressure, heart 
rate, and respiration were usually, though not always, produced, 
they returned to normal as soon as the stimulation was discon- 
tinued while in direct pressure stimulation of the spine the blood 
pressure remained increased for several minutes after the stimula- 
tion was removed. (Fifteen dogs were used in this series and de- 
tailed reports were given in the results of the original description 
of the work.) 

The above results relative to stimulation and inhibition 
have been reported in detail on seven of the animals for the purpose 
of showing the reason for the following conclusions: 

1. That osteopathic manipulation to the mid- or lower 
cervical and upper dorsal regions causes an increase in blood pres- 
sure and as a rule a slight increase in rate and amplitude of heart 
beat. 

2. Osteopathic manipulation when applied to the mid- and 
lower dorsal or lumbar regions produces a reduction of systemic 
blood pressure, while the respiration and heart beat remain un- 
affected or are slightly increased. 



538 PHYSIOLOGY : 

3. We have not been able to demonstrate in this series of 
work that there is any essential difference between osteopathic 
stimulation and inhibition when applied to the same area of the 
spine. 

4. That osteopathic manipulation or inhibition when applied 
to spinal regions, and which do not effect a correction of any struc- 
tural perversion, are not always followed by specific effects. 

5. That osteopathic manipulations when applied to various 
regions of the spine are neither specifically stimulatory nor inhibi- 
tory unless by such treatment a correction of some structural 
perversion is effected. 

6. In most animals all kinds of manipulative treatment 
are to some extent stimulatory in nature, except pressure which 
is applied over nerve trunks or over the so-called " peripheral 
centers" for long periods of time. This may be explained by 
the law, " over-stimulation equals inhibition," but we question 
if this applies to manipulation of the spine. 

7. That treatment of a certain spinal area in most cases 
is followed by physiological effects which depend upon the function 
of the nerve supply of structures innervated from these spinal 
segments; as, for example, the almost constant increase in blood 
pressure obtained from manipulation of the lower cervical and 
upper thoracic region. It may be argued that the quite constant 
results obtained from certain so-called inhibitory treatments, 
such as that used in diarrhea, would tend to conflict with the 
results given above, but we would remind the reader that the 
function of the splanchnic nerves to the intestines is normally 
that of inhibition to the peristalsis, and therefore decreased peri- 
stalsis would result from stimulation rather than from inhibition. 






CHAPTER LVIL 
SERIES NO. 9. 

SOME IMMEDIATE EFFECTS OF DORSAL 
LESIONS ON VISCERAL REFLEXES. 

L. G. Robb, D. O. 

While working on " movements of the alimentary canal" with 
the various classes * * * I noticed an occasional animal whose 
reflexes were diametrically opposite to* what had been designated 
as normal — i. e., a reflex inhibition of peristalsis as a result of 
stimulation of a peripheral spinal nerve. In seeking an explana- 
tion of this I examined the spine and invariably found a lesion, 
or lesions, in the splanchnic region, more likely at the seventh, 
eighth, or ninth dorsal, although some were above and some 
below this. 

These lesions were generally in the form of rotations (an 
occasional scoliosis was found) and rather pronounced — i. e., 
were visible after removal of the skin and fascia and were easily 
reduced in the dead animal. 

Problems. — 1. May a spinal lesion affect the normal spino- 
sympathetic reflexes; if so, does it inhibit or accelerate the action 
of the region involved? 

2. Is this action constant? 

3. Is only one or are all functions of the involved nerves 
affected? 

Lesions. — The animals in all cases (fifteen animals were 
used) were first normalized, then while the anesthesia was deep, 
traction was applied to the caudal part of the body with the 
cephalic end fixed, or vice versa, then the body flexed and rotated 
with the point of lesion fixed. 

539 



540 PHYSIOLOGY : 

Results. — It must be borne in mind that only the immediate 
effects of the lesion are dealt with in this article. 

Summary. — 1. Stimulation of the central end of the sciatic 
or branch of the brachial plexus after lesion (rotation) in the 
mid- or lower dorsal region causes a peristalsis in the stomach 
and a minimal rise in blood pressure, which may or may not stop 
on removal of the stimulus. If a peristalsis is already progressing 
this stimulus will increase its amplitude. 

2. Production of a lesion is sometimes sufficient to produce 
a persistent spontaneous peristalsis. 

3. An anti-peristalsis is occasionally observed, which is 
apparently due to an action of the splanchnic nerves. 

Conclusion. — An acute lesion will affect the normal spino- 
sympathetic reflexes. This action is inhibition to the function 
of the parts involved. 

The fact that a reverse peristalsis was obtained in some cases 
and the same effect, preceded by a vaso-constriction and viscero- 
dilation, was produced by stimulation of the peripheral end of 
the splanchnic nerve, would lead one to think that this might 
affect all or only a part of the functions of the nerves involved, 
or, if such a thing be possible, a perverted action of the involved 
nerves. This action is surprisingly constant, although it varies 
greatly in degree. 



CHAPTER LVIII. 
SERIES NO. 10. 

SOME IMMEDIATE EFFECTS OF BONY 
LESIONS UPON VASCULAR REFLEXES. 

J. Deason and C. L. Doron. 

The purpose of this series was to determine the effect upon 
dorsal, and lower cervical lesions upon: Blood pressure; rate 
and amplitude of heart beat. 

Methods Employed. — Animals used: dogs, nine; cats, 
two. Anesthetic, ether given by means of a tracheal cannula, 
and in all cases deep and constant. The sciatic nerve was sec- 
tioned and stimulation applied to the central end by a medium 
faradic current. The blood pressure was taken from the carotid 
or femoral arteries by the usual manumetrical method. Respira- 
tion was taken from a tambour attached to the tracheal cannula 
by a T-tube. Normal tracings were taken on all animals before 
they were lesioned. 

Lesions were made by traction and rotation of the cephalic 
end, with the lower cervical or upper dorsal fixed. Most lesions 
were in the sixth and seventh cervical, the dorsal lesions being 
difficult to obtain and make permanent. 

Literature. — Very little or no literature can be found on 
this subject, since only a comparatively small amount of work 
has been done along these lines. This series bears the same 
relation to vascular reflexes that series No. 9 does to visceral re- 
flexes. 

Results. — As has been proven many times, stimulation 
applied to the central end of the sciatic or any mixed or sensory 
nerve causes an increase in respiration, heart beat, and blood 

541 



542 



PHYSIOLOGY : 



pressure. The following is the table of the results obtained upon 
blood pressure and rate and amplitude of heart beat by stimulation 
applied to the central end of the sciatic: 





BEFORE 


LESION. 




Animal 










Blood 


No. 


Rate 




Amp. 




Pressure 


1 Dog 


Inc. 


10% 


Inc. 


Inc. 


7 m. m. 


2 Dog 


Inc. 


10% 


Inc. 


Inc. 


6 m. m. 


3 Dog 


Inc. 


2% 


Inc. 


Inc. 


2 m. m. 


4 Dog 


Dec. 


4% 


Inc. 


Inc. 


4.5 m. m. 


5 Dog 


Dec. 


2% 


Dec. 


Inc. 


13 m. m. 


6 Dog 


Inc. 


2% 


Same 


Inc. 


9 m. m. 


7 Cat 


Inc. 


2% 


Inc. 


Inc. 


9.5 m. m. 


8 Cat 


Inc. 


2% 


Inc. 


Inc. 


6 m. m. 


9 Dog 


Inc. 


10% 


Inc. 


Inc. 


8.2 m. m. 


10 Dog 


Inc. 


4% 


Inc. 


Inc. 


4 m. m. 


11 Dog 


Same 


Same 


Inc. 


4 m. m. 


Average 


Inc. 


2.9% 


Inc. 


Inc. 


6.6 m. m. 






AFTER 


LESION. 




Rate 




Amplitude 


Blood Pressure 


No change 




No char 


Lge 


Dec. 


9 m. m 


Inc. 8% 




No char 


Lge 


Inc. 


2.5 m. m 


Inc. 1.8% 




No char 


ige 


Dec. 


2 m. m 


Inc. 2% 




Increase 




Dec. 


15.5 m. m 


Inc. 2% 




No char 


Lge 


Dec. 


9 m. m 


Dec. 1% 




No change 


Dec. 


9.5 m. m 


No change 




No change 


Dec. 


7.2 m. m 


No change 




No change 


Dec. 


4 m. m 


Inc. 9% 




No change 


Inc. 


3.5 m. m 


No change 




No change 


Dec. 


6 m. m 


No change 




No change 


Dec. 


2.6 m. m 


Inc. 2.3% 




No change 


Dec. 


5.3 m. m 



It will be noted from these results that before the lesion 
was caused the blood pressure was increased by stimulation to 
the central end of the sciatic, this increase ranging from two to 
13 m. m., with an average of 6.6 m. m. After lesion was pro- 
duced the same stimulation caused a decrease in blood pressure 
except in two cases. This decrease ranged from 2 to 15.5 m. m., 
with a general average of 5.3 m. m. In the first of the exceptions 
(Dog No. 2) the increase in heart beat was excessive, yet the 
blood pressure did not increase as much as before the lesion. In 
the second case (Dog No. 9) the heart beat was less than before 
lesion, but not enough to account for the change in blood pressure. 

The rate of heart beat after lesion was not materially increased 
except in two instances. The amplitude, which before lesion was 



GENERAL AND OSTEOPATHIC. 543 

increased by stimulation, showed no increase after lesion except 
in one case, and that was very slight. All of these results were 
obtained within thirty or forty minutes after the lesion was 
made. After that time the normal function was regained. When 
a subluxation was obtained that was permanent the normal func- 
tions were not regained. These were only obtainable in small 
dogs. When a greater strength stimulus was used after the 
lesion than before, normal functions were obtained. 

Summary. — Stimulation of an afferent or mixed nerve 
caused a fall in blood pressure and a decrease in heart rate and 
amplitude with a bony lesion in the region of the cardio-autonomics. 
Conclusion. — The above results corroborate the findings 
obtained in Series No. 9; i. e., an acute lesion will affect the 
normal spinal sympathetic reflexes. This action is an inhibition 
to the functions of the parts involved. That the fall in arterial 
pressure was not due entirely to the rate and amplitude of heart 
beat can be seen from the results obtained. Stewart states (sixth 
edition, pages 167-8) that freezing of the cord in the lower cervical 
region causes a marked fall in blood pressure due to loss of vaso- 
constrictor tone. May this decrease in blood pressure, as a result 
of an osteopathic lesion, not be caused by the block of the vaso- 
constrictor fibers in this region, causing a loss of tone in the artery 
walls and a corresponding fall in blood pressure? It is also possible 
that the stimulus, failing to be communicated to the heart and 
blood vessels through the nerves of the lower cervical and upper 
dorsal regions, reaches these structures by way of the vagi, re- 
tarding the heart action and causing a vaso-dilation. 

Effects of Osteopathic Lesions Artificially Produced, 
Not Due to Spinal Shock. — It has been suggested by certain 
research workers in physiology in the medical schools that the 
results obtained from the produced lesions in animals by osteo- 
pathic workers might be due to spinal shock. The physiological 
meaning of " spinal shock" is that there are certain well-marked 
and far-reaching disturbances of the central nervous system 
which result from trauma to or partial or complete section of the 
spinal cord. There is no reason for discussing here the various 



544 PHYSIOLOGY : 

theories of spinal shock, but we shall try to show that the results 
obtained by us could not be explained by this phenomenon. 

1. The osteopathic lesion affects particularly the nervous 
system supplying visceral structure (spinal autonomics). The 
skeletal musculature being less often affected, just the opposite 
to this occurs in spinal shock; viz., the skeletal muscles are most 
often involved. Sherrington states as follows: 

"It is noteworthy that spinal shock takes effect on just those 
tissues which waste when the synaptic nervous system is de- 
stroyed, namely, the skeletal muscles. When the primitive diffuse 
nervous system, the nerve-net, exists as in the visceral and vascular 
musculature, neither spinal shock nor atrophy occurs consequently 
to spinal transection * * * and after total transverse section of 
the cord in man the depression of function of skeletal muscula- 
ture is profound and practically permanent. On the other hand, 
the depression of visceral function seems hardly greater in man 
and the ape than in rabbit or frog." 

2. Quoting again from Sherrington, "The shock takes 
effect almost exclusively in the aboral direction," which fact 
has been corroborated by most workers on this subject. On 
the other hand, the effects of osteopathic lesion may and, as a rule, 
will, involve structures on either or both sides (cephalic and caudal 
to the point of vertebral separation) equally. 

3. Spinal shock materially affects the blood pressure, caus- 
ing a marked decrease, and destroys the vasomotor reflexes. 
Sherrington states: "When in the dog complete transection of 
the spinal cord through the eighth cervical segment is practiced, 
a severe fall in general arterial blood pressure ensues, and vasomotor 
reflexes cannot be elicited." 

The effects of the bony lesion produced in this area (see Series 
Nos. 2 and 8) are, as a rule, just the opposite to this, viz., that 
an increase in blood pressure and often an increase in rate and 
amplitude of heart beat result. The production of the lesion, 
that is, the possible effect or effects of manipulations used by us 
or the "strain" on the nervous system following these manipula- 
tions, could not be due to spinal shock because no marked fall in 



GENERAL AND OSTEOPATHIC. 545 

blood pressure has ever been found, and the vasomotor reflexes 
are never completely destroyed. The fact that lesion or " spinal 
strain" in some araes of the spine produce an increase in blood 
pressure, while in other areas the opposite effect is produced, 
and the fact further that no such effects are obtainable from 
spinal shocks, again differentiates them. 

4. Paralysis, partial or complete, of certain muscles or groups 
of muscles, according to the extent of the lesion, is common in 
spinal shocks. This is not true of osteopathic lesions. Of all 
the animals operated in this laboratory (about 140 dogs, cats, 
and monkeys), not a single animal has ever shown any signs of 
paralysis. There was often tenderness about the affected part, 
but no symptoms of direct injury to the cord, and therefore no 
symptoms comparable to spinal shock. Extreme care was always 
exercised to not produce complete luxations, and there was never 
a case of bony fracture, ligamentous tear, or complete luxation 
produced from our attempts to produce subluxations or what 
may properly be termed osteopathic bony lesions. We have, of 
course, not obtained functional disturbances from every attempted 
lesion, but by far the greater number of such attempts have 
followed by functional disturbances, and this could not have been 
due to spinal shock. 

5. The blood pressure effects from spinal bony lesion last 
several minutes, after which (if the lesion is only a spinal strain, 
i. e., if it is not a permanent subluxation) it returns to normal. 
This effect is somewhat similar to spinal shock, except that the 
time necessary for normalization is much longer. If the shock 
is due to complete transection, several days are necessary for 
recovery. It might be argued that because the higher animals, 
man included, are more susceptible to spinal shock, and recovery 
occurs slower, in the human the effects which we hold as being 
results of bony lesions could be due to spinal shock. This, we 
believe, is hardly tenable, for the following reasons: 

6. In case of spinal shock, recovery of the structures sup- 
plied by the autonomic nervous system (visceral structures) 
occurs, which varies directly with the time and inversely with 



546 PHYSIOLOGY : 

the phylogenetic developmental stage of the animal in question. 
On the other hand, as a rule, the effects of a permanent bony lesion 
increase with time. That is, in case of lesions of long standing 
the perversion of physiological effects and the extent of patho- 
logical change is also increased. 

7. Spinal Shock and Spinal Strain. — Since the phe- 
nomena of spinal shock are insufficient, what is the explanation 
of perversion of certain physiological functions following slight 
subluxations of vertebrae and other joints? With the experimental 
information which we now have at hand it is safe to say that 
subluxations due to trauma, muscular contractions, decreased 
tone in ligaments and muscles about the joint, etc., may be capable 
of producing widely different effects. The first, the subluxation 
due to trauma, is comparable to the artificial bony lesion, and 
this we may say produces its effects by spinal strain. By spinal 
strain is meant the effects on the nerves in the immediate relation 
with the joint or joints involved. The stretching or compression 
of the joint structures might, by mechanical stimulation to either 
the efferent or afferent nerve elements, produce an increased 
activity of these fibers or nerve trunks. This, if the perverted 
structural relations are not permanent, would be temporary and 
a corresponding temporary inhibition or decreased functional 
activity of the nerve elements would follow, which lasts for vary- 
ing lengths of time, after which normal functional activities of 
the nerves may be demonstrated. The fact that a temporary 
increase in blood pressure, etc., followed by a decrease, usually 
follows such manipulations tends to substantiate this theory. 
This explanation alone, however, is hardly sufficient for a complete 
explanation of all the results that follow "spinal strain." 

What, for example, is the explanation of the decreased activity 
of the efferent nerves from segments of the spine which are so 
lesioned? Why are the blood pressure, heart beat, etc., not 
increased by stimulation of the central end of an afferent or 
mixed nerve after a " spinal strain" has been produced in the 
upper thoracic region as much as before? Why do not the splanch- 
nics inhibit peristalsis of the intestine from stimulation of a sensory 



GENERAL AND OSTEOPATHIC. 547 

nerve after lesion in the mid- or lower thoracic as they almost 
invariably do before such " spinal strain" was effected? 

The fatigue of the nerve elements may and probably does have 
much to do with this, but we believe the disturbance' of both the 
afferent and efferent vascular elements plays a more important 
part. It is known that the functional activity of the neuron 
varies directly with the arterial supply and the venous drainage. 
This is readily understood when we consider the nerve cell as any 
other cell and that it must have oxygen and other food elements 
from the blood, that it may be able to function normally. Fur- 
thermore, it must have a good drainage, that its carbon dioxide 
and other products of metabolic waste may be removed. As 
Sherrington so excellently puts it, "In the first place, nerve cells, 
like other cells, lead independent lives — they breathe, they 
assimilate, they dispense their own -stores of energy, they repair 
their own substantial waste; each is, in short, a living unit with 
its nutrition more or less centered in itself. Here, then, problems 
of nutrition, regarding each nerve cell and regarding the nervous 
system as a whole, arise comparable with those presented by all 
other living cells." This explanation as offered here relative to 
the blood supply for the decreased activity of nerve tissue was 
not borrowed from the old stock answer given by most osteopaths 
when asked how the lesion produces its effect. It is not an answer 
given from hasty evidence or none, as we often hear the answer 
"Nature does it." It is not a guess at which we have blindly 
jumped or a shield behind which we may conceal our supreme 
ignorance, but a scientific conclusion at which we have arrived 
after having given careful consideration to the experimental 
evidence at hand. 

Drs. McConnell and Farmer have found that the structures 
about the joint after such lesions were produced were much con- 
gested, and we have found the same to be true. We have found 
further that it is not possible to obtain normal efferent effects 
by afferent stimulation until long after the immediate effects of 
the "spinal strain" have seemingly ceased. We have found that 
the stimulation of the efferent nerve trunk after stimulation 



548 PHYSIOLOGY : 

produces normal functional effects as it did before lesion, there- 
fore the trouble must lie within the cord or other seat of nerve- 
cell origin. Just here, by way of explanation, we should say 
that by this the explanation of the decreased functional activity 
of the spinal autonomics from reflex stimulation after spinal 
lesion, as has been demonstrated in this and the preceding series 
(No. 9), depends upon the structural and functional differences 
between the conducting mechanism in nerve trunks and the reflex 
arcs of the cord, particularly the synaptic arc. 

The conductivity in the reflex arc presents many character- 
istic differences from that of nerve trunks, as follows: " Slower 
speed as measured by the latent period between application of 
stimulus and appearance of end-effect, this difference being greater 
for weak stimuli than for strong. " * * * " Fatigability in contrast 
with the comparative unfatigability of nerve trunks." * * * "Much 
greater dependence on blood circulation, oxygen." (Verworn, 
Winterstein, V. Baeyer, etc.) It is, then, this intercellular con- 
necting mechanism, that which carries the energy from axon to 
dendrite within the gray matter of the cord and is transmitted 
to or serves to excite to activity the intracellular energy of the 
efferent neuron, which is most affected and which offers resistance 
to the passage of impulses in reflex block. It has been shown 
(Series Nos. 2, 5, 8, and 9) that this condition, which we may 
now call reflex block, is maintained as long as the structural per- 
version (bony lesion) is maintained, and that a return to normal 
always results from five to sixty minutes after the vertebral per- 
version has been released. This time allows for the normaliza- 
tion of the blood supply to the synaptic portion of the reflex arc. 
We are, of course, referring to the immediate effects of experi- 
mental bony lesions and not to chronic lesions. 

By this explanation we do not mean to exclude all possible 
effects of direct nerve stimulation by mechanical pressure to the 
nerve trunk or to sensory endings in or about the joint. We 
know of no experimental evidence to show that direct nerve 
stimulation is not a possible explanation of certain phenomena 
following bony lesions; but this will be discussed in another series 
in which some work has been done along this line. 



CHAPTER LIX. 
SERIES NO. 12. 

VERTEBRAL LESIONS AND OSTEOPATHIC 

THERAPY. 

J. Deason, D. 0., and A. R. Bell, D. O. 

The purpose of this series of experiments was to try the effects 
of osteopathic lesions on monkeys, and if possible, after func- 
tional disturbances had occurred, following the production of 
bony lesions, to determine the effects of corrective manipulations 
on these animals. Monkeys were selected for this work because 
of their closer resemblance, structurally and functionally, to the 
human species. 

Literature. — Animal experimentation for the purpose of 
determining the effects of osteopathic bony lesions on functional 
disturbances, pathological changes, etc., has now been done on 
hundreds of animals and by different workers, the published 
results of which should be common knowledge to every student 
and graduate of osteopathy. * * * 

Care of Animals. — Each monkey was kept in a separate 
cage, an iron frame covered with wire netting, the floor of which 
was of hardware cloth under which was a zinc pan for the purpose 
of draining the urine into containers. Each cage was 30x30x20 
inches, which gave the animal plenty of room. These cages were 
cleaned regularly by washing with a hot-water and steam hose. 
The animals were fed twice daily and the diet kept as regular' 
as possible, which consisted of apples, corn, cabbage, parsnips, 
toasted bread, etc. 

Normalization. — Samples of urine were taken daily and 
analyzed. (The methods described in Series No. 4 were followed.) 

549 



550 physiology: 

The character, consistency, and amount of feces were noted, 
the appetite was observed, and the weight of each animal 
recorded. All animals were kept from four to six weeks under 
observation before they were lesioned. Monkeys Nos. 2, 3, 4, 
and 10 died from pneumonia within three weeks after they were 
received, but only one other animal (monkey No. 11) showed any 
symptom of disease during normalization, and this case will be 
recounted later. 

During normalization all animals either remained constant 
or gained in weight except No. 11, which lost weight from 2,200 
to 1,800 grams. This monkey had tuberculosis when received. 

No. 1. — Young Java monkey, increased in weight from 850 to 900 grams. 

No. 5. — Rhesus monkey, increased in weight from 1,545 to 1,625 grams. 

No. 6. — An old ring-tailed monkey, increased from 1,765 to 1,800 grams. 

No. 7. — Ring-tailed monkey, remained almost constant in weight at 
1,000 grams. 

No. 8. — Rhesus monkey, gained in weight from 2,000 to 2,400 grams. 

No. 9. — Ring-tailed monkey, increased in weight from 1,000 to 1,050 
grams. 

No. 12. — Rhesus monkey, remained almost constant in weight at 2,400 
grams. 

The fact that these animals remained constant or gained 
in weight during the period of normalization shows that they 
had good care and were free from disease up to the time of lesion. 
There were no symptoms or signs of disease (other than No. 11, 
given above), except occasional variations in urinary findings, 
the reasons for which will be stated later. 

Methods of Producing Lesions. — The animals were placed 
under deep ether anesthesia and lesions produced by fixing the 
vertebra at the point desired and rotating the animal's body. 
In some instances it was only necessary to manipulate the pro- 
cesses of the vertebra between the thumb and fingers to effect 
rotation, but in most cases we tried to produce lesions which 
would involve two or more segments at the same time. All 
lesions produced were rotations. We were always careful in the 
production of lesions to not cause sufficient trauma to in any 
way produce a fracture or ligamentous strain, therefore no trau- 
matic effects to the cord were ever produced. 



GENERAL AND OSTEOPATHIC. 551 

Results. — The functional disturbances following lesion in 
each animal will be given under headings significant of the disorder 
produced, for the purpose of clearness. 

NUTRITIONAL DISTURBANCES FOLLOWING LESIONS IN THE 
UPPER THORACIC REGION: 

Monkey No. 5. — Lost in weight from 1,625 to 1,425 grams during four 
weeks following lesioning. After the lesion was corrected this animal increased 
in weight to 1,520 grams in two weeks. 

Monkey No. 7. — Lost in weight from 1,020 to 900 grams during two weeks. 
Correction of the lesion was not tried. (See special note on No. 7.) 

Monkey No. 8. — Lost in weight from 2,400 to 2,075 grams during four 
weeks and regained to 2,225 two weeks after lesion was corrected. 

Monkey No. 9. — Showed a slight gain for one week and then lost from 
1,050 to 925 grams during the three following weeks. Two weeks after cor- 
rection of lesion this animal gained in weight to 1,000 grams, its normal weight. 

Monkey No. 12. — Lost in weight from 2,400 to 2,112 grams during four 
weeks following lesioning, and regained to 2,150 two weeks after lesion was 
corrected. 

Monkeys Nos. 1, 6, and 7. — Were kept for control; i. e., they were kept 
unlesioned on the same food supply in the same room, with all environmental 
conditions the same. During all this time monkey No. 1 showed a constant 
gain from 900 to 1,000 grams. Nos. 6 and 7 remained constant in weight. 

This we believe controls the experiment quite well, and the 
cause for this loss in weight of the four lesioned animals would 
seem to be the thoracic lesion. By reference to the above dis- 
cussion on normalization it will be seen that only normal animals 
were used and that those which had been showing a constant 
increase in weight during the period of normalization showed 
a marked decrease after lesioning. We should not, of course, 
be so hasty as to conclude that the upper thoracic lesions are 
always followed by loss in weight, nor would we ever assert posi- 
tively that the lesions were responsible for the decrease in weight 
in these cases. Too few animals have been tried and the test 
has not continued long enough to make positive statements. 

INTESTINAL DISTURBANCES FOLLOWING THORACIC 

LESIONS. 

Seven monkeys were lesioned, some in the mid- and some 
in the lower thoracic region. Intestinal disturbances and varia- 
tions in the urinary findings were noted after these lesions. The 
results of urinalysis are given later. The intestinal changes only 
are to be given under this heading. 



552 fhysiology: 

Monkey No. 1 showed no symptoms at all that we could observe; there 
was no diarrhea nor constipation at any time. 

Monkey No. 5.— The next day after lesioning this animal had a marked 
diarrhea, which increased for one week, when the lesion was corrected. 
After correction of the lesion the diarrhea stopped and remained normal for 
a week, when the lesion was reproduced. This was followed by diarrhea as 
in the first instance, except that it was more severe. Nine days later the 
lesion was corrected, and, as before, this treatment was followed by an im- 
mediate cessation of the diarrheal condition. This monkey was lesioned a 
third time, twelve days later, which caused the same symptoms, but this 
time treatment seemed only to offer a temporary relief. We were never able 
to stop the condition, which grew constantly worse until the animal was killed, 
one month later. There was some loss of weight during this time, but we 
think this was probably due to the extreme diarrheal condition, rather than 
any interference with systemic metabolism, as the animal's health was other- 
wise good. 

Monkey No. 6. — Showed no intestinal disturbances, but was only kept 
in lesion a few days. (See special discussion of Monkey No. 6.) 

Monkey No. 7. — Showed a slight diarrhea for a few days only. Correct- 
ive treatment was not tried. (See discussion on No. 7 elsewhere.) 

Monkey No. 8. — Showed a slight diarrhea the following day after lesion- 
ing. This continued so for fifteen days, when the lesion was corrected. The 
diarrhea stopped and stools remained normal for a week, when the animal was 
re-lesioned. Diarrhea again occurred, which lasted for a week and stopped 
after a second correction of the lesion. The diarrhea was never severe in 
this animal, and there was a constant increase in weight during the entire 
time. 

Monkey No. 9. — Showed no diarrhea or constipation after these lesions 
and the weight remained nearly constant. 

Monkey No. 11. — A severe diarrhea developed in this animal after lesion- 
ing, and as in No. 5, immediately stopped after the lesion was corrected. 
This animal was lesioned in both upper and lower thoracic regions, but was 
not tried a second time. (See discussion No. 11 below.) 

No. 12. — After lesioning this animal showed diarrhea almost immediately, 
which continued for one week and stopped after correction of the lesion. The 
animal was re-lesioned seven days later, and a diarrhea appeared which, 
though not so severe as in No. 5, continued for three weeks, when corrective 
treatment was followed by normal feces. This animal continued to gain in 
weight during the time of lesion. It was kept unlesioned for one month 
longer, when it was killed for pathological examination. No diarrhea appeared 
during this last month and the weight increased in greater proportion than 
during the period of lesion. 

URINARY FINDINGS. 

Samples of urine, free from feces and other contamination, 
were collected daily when obtainable. 

Following is a summarized record of each animal used: 

Monkey No. 1. — Seven analyses, covering a period of five weeks, were 
made. During the time of normalization and on one day only was sugar 
found. This amounted only to a slight trace and might be explained by the 
fact that an excess of bananas was given in the diet at this time, which seemed 



GENERAL AND OSTEOPATHIC. 



553 



to produce alimentary glycosuria. The lesion produced was in the mid-dorsal 
area of the spine. On the second day after the production of the lesion sugar 
appeared in the urine and continued to show for ten days. The amount present 
averaged one per cent daily for the entire ten days. 

Monkey No. 5. — During the time of normalization this animal showed 
an average of .2% sugar in its urine. At the same time, the monkey gained 
100 grams in weight, which would tend to show that the glycosuria was of 
the alimentary type, since in pathological glycosuria loss of weight invari- 




Fig. 72. — Section of kidney showing albuminous degeneration, 
lesioned in lower thoracic region. X 120 diameters. (Reduced 20%.) 



Taken from monkev 



ably occurs. A mid-dorsal lesion was produced and in the eight days fol- 
lowing the average daily elimination of sugar was .50%. After correction of 
lesion this animal showed an average of .2% of sugar for two consecutive 
days, and for the following six days the urine was absolutely free from sugar. 
During period of lesion this animal lost constantly in weight. 

Monkey No. 8. — During time of normalization seventeen analyses were 
made. For seven days of this time the daily average was .24% of sugar. 
(It was during these days that the banana diet was used.) During the re- 
mainder of the normalization period the urine was free from sugar, giving a 
daily average of .1% for the entire time. After the production of a mid- 
dorsal lesion the urine showed a daily average of .4% of sugar for the follow- 
ing ten days. 

After reduction of the lesion analyses were made for the following five 
days. These showed slight traces of sugar for the first two days and sugar- 
free urine for the remaining time. 



554 



PHYSIOLOGY I 



Monkey No. 9. — During the normalization period nine analyses were 
made. The daily sugar average was .08%. This animal was kept in lesion 
one week and during that time showed a daily average sugar elimination of 
.30%. After reduction of the lesion, sugar-free urine was voided. 

Monkey No. 11. — This animal was normalized for a period of four weeks. 
Seven analyses were made during this time and only once was sugar found. 
This gave a total daily average of .05%. For the following ten days, after 
the production of a mid-dorsal lesion, this animal showed sugar every day 
except two, giving a daily average of .36%. Correction of lesion in this animal 
was not effected. 






Warn*' " * v-i. «►•* .♦•*i >> «& 







*f » - 









•4»J 



Fig. 73. — Section of liver taken from monkey lesioned in mid-thoracic, showing small 
abscess and albuminous degeneration. X 120 diameters. (Reduced 20%). 



Monkey No. 12. — Normalization record was kept on 
one month, during which time eight analyses were made, 
daily average of .14% sugar. A mid-dorsal lesion was 
urine on the following day showed sugar and continued to do 
The average amount during this period was .48% daily, 
were made after correction, which showed a daily average of . 

The presence of sugar in the urine during the 

malization was in all probability due to an excess of 

given in the diet, as the sugar appeared in all the 

at a time when simultaneously bananas were 



this animal for 
These showed a 
produced. The 
so for eight days. 
Eleven analyses 
06%. 

period of nor- 

bananas being 

animals' urine 

being heavily 



GENERAL AND OSTEOPATHIC. 



555 



fed. After taking the bananas from the diet and using grain and 
acid fruits instead, the sugar elimination ceased. This same diet 
of grain, apples, etc., was used during the times of lesion and 
following correction and was kept constant, no variations being 
made in it. 

Summary. — All animals used showed a much increased 
amount of sugar elimination during time of lesion, which was 



"5 *A 




Fig. 74. — Section of pancreas from monkey lesioned in mid- and lower thoracic regions. 
Islands of Langerhans show fibrosis. X 120 diameters. (Reduced 20%.) 

either greatly reduced or entirely eliminated when the bony 
subluxation was corrected. We believe the sugar elimination 
to have been pathological, as the animals constantly lost weight 
during the same time. 

The presence of such amounts of sugar as appeared during 
the time the animals were in lesion definitely shows this: That 
in some manner bony subluxations produced in the mid-dorsal 



556 physiology: 

region of the spine deranged body metabolism, and caused func- 
tional disturbances of the nutritional processes. 

OTHER FUNCTIONAL DISTURBANCES FOLLOWING LESION. 

Monkey No. 7. — This animal was kept under observation for fifty-eight 
days before lesioning. During this period the animal was in perfect health 
and increased some in weight. After lesion in the upper and mid-thoracic 
region the animal lost in weight from 1,020 to 900 grams in two weeks. It 
then contracted pneumonia and died in three days after the first symptoms 
appeared. On post-mortem the lungs were found badly congested. 

Monkey No. 11. — This was a female Rhesus monkey seemingly in good 
health, except that it coughed occasionally. Bacteriological examination 
of throat smears failed to show any specific infection. After lesion in upper 
dorsal there was an extreme diarrhea, and the cough grew worse. The 
diarrhea stopped after corrective treatment applied to the lower thoracic 
region, but the cough and other symptoms increased. The animal was now 
losing weight very fast. It seemed to be hungry and ate well, but gradually 
grew weaker and became very inactive. Extreme swelling of the face region 
and much cyanosis had developed one week later, when it died. Post-mortem 
examination showed a general systemic acute miliary tuberculosis. Practically 
every visceral structure was involved. In this case we are quite sure that the 
animal had tuberculosis when it was recieved, but certainly in these two 
animals there is much reason to believe that the lesions acted as in the one 
case (No. 7) predisposing, and in the second case (No. 11) an exciting factor 
to the infective processes. 

Monkey No. 6. — This was an old ring-tail, but was in good physical 
condition when received and remained so for two weeks. The appetite was 
good and the urine and feces were normal. At this time it received a severe 
fall. Its keeper accidentally threw it hard against the floor when it tried to 
bite him. The animal gave evidence of an injured neck; after four days 
it was not so lively and seemed ill; ten days later there was trouble with 
its right arm; it would put the left arm only out for food and did not use 
both hands ambidexterously as formerly, and as all monkeys do while eating. 
A few days later the right leg was involved. This gradually progressed until 
the right arm was completely spastic. The left limbs were also involved and 
the left arm showed signs comparable to intentional tremor when it reached 
for food. It was very irritable during the entire time. After death, on post- 
mortem examination, the atlas and axis were both found to be slightly anterior 
and rotated to the right. There were no other bony lesions, nor was there 
any evidence of trauma to the cord. We think the symptoms could not be 
explained by the theory of "spinal shock." Probably the term " spinal 
strain" of an extreme type, some of the effects of which have been given in a 
previous series, would explain the causes in this case. 



GENERAL AND OSTEOPATHIC. 557 

REPORT ON PATHOLOGY. 

T. L. McBeath, D. 0. 

The animals were killed by administering ether, and were 
posted by Dr. Deason and myself. 

Pancreas. — Shows infiltration of fibrous tissue running in 
between the glandular structure. The islands of Langerhans 
show fibrosis (fibrous tissue surrounding and infiltrating into the 
glandular structure of the islands). 

Kidneys. — Show slight albuminous degeneration in the first 
convoluted tubules in cortical area, the renal epithelium is frayed 
into the lumen, and the cytoplasm appears granular. 

Liver. — Outline of cell membrane intact, the cytoplasm 
slightly granular in intermediate portion of lobules; also small 
abcess near hepatic artery, showing accumulation of polymorpho- 
nuclear leucocytes in surrounding tissue, causing slight necrosis 
of tissue. 



CHAPTER LX. 
SERIES NO. 15. 

CONTROL WORK ON MAMMALIAN SERIES 

NOS. 2 AND 7. 

H. L. Collins and Chas. R. Eitel. 

Since the result of Series No. 7 done by us last year dovetail 
so nicely with the work done by Doctors Deason and Robb in 
Series No. 2, the result of one series strongly supporting the other , 
it seemed advisable to continue the work on this series. As our 
work along this line was simply to act as a control on mammalian 
Series Nos. 2 and 7, it would not be necessary to give any 
lengthy detailed account here, but just a few statements of our 
findings, which will be self-explanatory. 

Seven dogs were used in this series. The methods and pre- 
cautions are the same as those used in Series No. 7. 

In almost every instance pressure, flexion, or manipulation 
in the lower cervical and upper dorsal regions, with a fixed point 
gave an increase in blood pressure. The fact was also confirmed 
that when flexion was applied to the vertebrae with no fixed point, 
there was not nearly as much variation produced as when a fixed 
point was established. In the few exceptions to these results 
there was a vertebral lesion found in some of the dogs which might 
have produced these contrary findings, but as there were so few 
of these negative results obtained and so many in the affirmative, 
we are forced to believe that manipulation, pressure, or flexion 
in the lower cervical and upper dorsal produces an increase in 
blood pressure, and the same movements, viz., pressure, manipu- 
lation, or flexion in the lower dorsal and lumbar produces a decrease 
in blood pressure. 

558 



GENEKAL AND OSTEOPATHIC. 559 

One interesting thing might be restated from the work done 
by Doctors Deason and Robb: When two different kinds of 
stimulation were used in one region they confirmed our results 
of Series No. 7. We will mention one instance here. When 
rotation and pressure were both applied to the upper lumbar 
a decrease in blood pressure in both instances was recorded. This 
not only helps to prove the statement of Series No. 2, but also 
upholds our findings, which are stated in Series No. 7. 

CONCLUSIONS. 

In summing up this problem we find: 

1. Vertebral movements, when applied to different areas 
of the spine, produce radically different effects, as has been stated 
in Series No. 2. 

2. That flexion of the spine, with a local fixation, gives 
more marked results than flexion without fixation. 

3. That the effects of muscular massage are inconsiderable 
as compared with spinal movement with fixation. 

4. The results of Series Nos. 16 and 17 confirm our findings 
and the results of Series No. 2, that manipulation of different 
areas of the spine produces not only different, but more or less 
specific, physiological results. 

These findings are confirmatory of Series No. 2, published 
in the April number of the Journal of Osteopathy, 1911, under 
heading "Some Physiological Effects of Vertebral Movements 
Experimentally Produced," and of Series No. 7, published in the 
July, 1912, Journal of the American Osteopathic Association. 



CHAPTER LXI. 
SERIES NO. 16. 

EFFECTS OF SPONDYLOTHERAPIG AND 
OSTEOPATHIC STIMULATION ON 
THE SECRETION OF URINE. 

C. A. Pengra and G. A. Alexander. 

It was the purpose of this series of experiments to determine 
as far as possible the effects upon the secretion of urine by the 
kidneys when stimulated by the application of spondylotherapic 
concussion and of osteopathic manipulation in the region of the 
spine, from which the nerve supply of the kidney is derived. 

It was not the purpose to determine the correctness of, nor to 
corroborate nor disprove, any theory that has been advanced 
regarding the secretion by the kidneys, whether it be the original 
theory of Ludwig that " urine is formed by the simple physical 
process of filtration and diffusion, " or the later theory of Bowman 
and Heidenhain, which assumes that " water and inorganic salts 
are produced in the glomeruli, while urea and related bodies are 
eliminated through the activity of the epithelial cells in the con- 
voluted tubules." (Howell.) 

The animals used were dogs, eleven in number, to ten of 
which ether was administered deeply and constantly by means 
of the tracheal cannula. 

The animals were not operated after anesthetization until 
such time as respiration became rhythmical and pulsation strong 
and regular, when an abdominal incision was made in the median 
line and both ureters cannulated, the cannula being long and 
extending out into graduated test tubes. Again, time was allowed 
for the rate of flow to become normal, i. e., to regulate itself after 
any possible shock of the operation to an even and regular flow. 
560 



GENERAL AND OSTEOPATHIC. 561 

Several counts were then taken about ten minutes apart to 
ascertain the exact rate of normal flow, after which stimulation 
was applied by concussion and manipulation to the regions indi- 
cated, sufficient time being allowed each time for the effects to 
be demonstrated and for normalization to occur. It will be ob- 
served that the increase in flow after osteopathic manipulation 
was applied invariably remained constant until the animal was 
killed, which was not brought about for a period, in many cases, 
of from one to two hours. 

The very noticeable variations in normal flow between the 
different animals experimented upon were due principally to 
variations in size, strength, and age, as of course uniformity in 
these qualities is impossible, although the strongest dogs obtainable 
were used in each instance and none but normal animals were 
operated upon. 

In the application of stimulation by means of spondylotherapic 
concussion, as suggested by Dr. Albert Abrarns in his book (second 
edition) on treatment, the concussion was applied by the use of 
a light hammer and a rubber cork, as a percussion pad, always 
lightly at first and gradually increased to heavy; but, as will 
be noted in the experiments listed, our best efforts failed to pro- 
duce the desired results by this method and, in fact, not the slight- 
est change in rate of flow was noted. 

The osteopathic manipulation was applied altogether by 
lateral rotation, making fixed points of the spines of two adjacent 
vertebrae. In order to know that the effects were being produced 
directly by stimulation of some nerve mechanism to the organ 
and not by increase in general blood pressure, or by any change 
in rate or amplitude of heart beat, or of respiration, the mercury 
manometer was attached to the carotid and the pneumograph 
to the trachea of the animal, but these instruments failed to 
record any variations which would be indicative of the changes 
sought in respiration or in general blood pressure. 

Following is a list of two of the dogs operated, the remaining 
nine not being listed for lack of space, but showing similar results : 



562 physiology: 

Dog No. 1. — Operated 2:45 p. m.; normalized 3:20 p. m. 

Four counts taken to ascertain the normal rate of flow showed the left 
ureter to be eleven drops per five minutes and the right to be ten drops per 
five minutes. 

At 3:45 p. m. percussion was applied; as stated above, without effect. 

At 4:00 p. m. osteopathic manipulations were applied, resulting in an 
increase of two drops per each ureter per five minutes or an increase of 20 
per cent. 

A second count taken at 4:25 p. m. showed a second increase of one drop 
per ureter per five minutes. 

At 4:40 p. m. the same manipulation applied to the same region resulted 
in increasing the flow of the right ureter to sixteen drops and the left to 
eighteen drops per five minutes, or more than 20 per cent. 

At 5 :00 p. m. the flow remained the same, and the dog was killed. 

Dog No. 11. — This animal was operated upon under aseptic conditions, 
ether being administered by means of a cone, after which it was thoroughly 
bandaged, the cannula 1 passing. to the outside through a slit in the gauze. It 
was then swung in an improvised hammock in a sterile cage, in such a manner 
that it could cause no injury to itself. 

Two hours after the dog had recovered from the effects of the anesthetic, 
counts were taken to ascertain the normal flow of urine, which was eleven 
drops per ureter for fifteen minutes. Osteopathic manipulation applied to the 
region of the twelfth and thirteenth dorsal increased the flow immediately 
to 18 drops per ureter per fifteen minutes. Another count thirty minutes 
later showed that the flow had again increased to 26 drops per ureter per 
fifteen minutes, a total increase of 136 per cent. 

The animal was then taken from the hammock and allowed to rest in 
the cage over night. At 9:00 a. m. the following day the animal's temperature 
was 37° C. (normal), but it seemed very thirsty; was given milk. 

A count was taken to ascertain the normal flow, which showed it to have 
remained almost constant during the night, being twenty-four drops per 
ureter per fifteen minutes. 

Because the animal seemed thirsty and the count still remained high, it 
would seem that the total amount of elimination had been much increased 
during the period. 

The same manipulations were applied as on the previous day, resulting 
in an increase to 36 drops per ureter per fifteen minutes. A second count was 
taken one hour later, showing that this increase had remained constant. 

This animal was examined thoroughly at 3:00 p. m. the same day and 
found to be in perfect condition, the temperature being normal and showing 
no signs of infection from the operation. 

SUMMARY AND CONCLUSION. 

J. Deason, M. S., D. O. 

The above series of experiments was done under my super- 
vision and I believe every possible precaution was observed to 
eliminate errors. 

The care and operative technic of these workers was ex- 
cellent. No animal suffered from shock due to unnecessary expos- 



GENERAL AND OSTEOPATHIC. 563 

ure. The greatest care was exercised in the handling of the ani- 
mals to avoid any undue mechanical stimulation, etc., and the 
results obtained could not possibly have been due to anything 
other than spinal manipulation. Further evidence of this was 
shown in Dog No. 11, which showed even a greater increase in 
urine secretion from spinal treatment than the animals while 
under the influence of ether. The increase, therefore, can not be 
attributed to the effects of the anesthetic or any careless handling 
while being operated. 

It may be suggested that the results came from massage of 
the spinal musculature, but that this is not at all probable we 
cite the reader to Series Nos. 2 and 15 of our mammalian experi- 
ments, which show that massage is neither so effective nor specific 
as osteopathic treatment. Those who wish to explain these 
effects by massage will first have to answer this question, viz., 
why is this excessive activity caused only by a specific kind of 
spinal treatment applied to a specific area, while other methods 
utterly fail? 

From the results of this work we may draw the following 
conclusions: 1. That spinal concussion, when thoroughly tested, 
produces absolutely no effect upon the functional activity of the 
kidneys; 2. That by proper osteopathic manipulations the 
functional activity (secretion) of the kidneys can be increased 
from 20 per cent, to 100 per cent., or even more; 3. That this 
increased activity lasts for a sufficient length of time to very 
materially reduce the body water content; 4. That there is a 
certain definite region of the spine (eleventh and twelfth dorsal) 
from which the autonomics originate, which controls the functions 
of the kidneys; 5. Since there are no changes in systemic blood 
pressure, this increased function of the kidneys is- due either to 
specific vasomotor or secretory (trophic) nerve fibers, which 
may be influenced without causing general systemic vasomotor 
changes; 6. That spinal treatment may be given in such a way as 
to be specific in effect, i. e., to effect only certain functions. 

Osteopathic Significance. — It has been shown, Series 
Nos. 4 and 12, that bony lesions of the lower thoracic and upper 



564 physiology: 

lumbar regions produced artificially in normal animals affect 
the normal functions of the kidneys. Clinically, many cases of 
kidney trouble have been demonstrated to be due to similar lesions. 

In this series it has been shown conclusively that the secretions 
of the kidneys can be increased from 12 per cent, to 100 per cent, 
by stimulatory treatment applied to the eleventh and twelfth 
thoracic segments of the spine. The secretion thus produced 
often remains increased for two or three hours or longer, during 
which time the water content of the body is greatly reduced. 

This same experiment has been tried with equal success on 
the human, and by this means in cases of febrile conditions the 
toxins of the body fluids and the temperature have been much 
reduced in a number of cases in which the test has been applied. 

The practical significance of such treatment is therefore appar- 
ent. If the toxin content of the blood can be materially reduced, 
as this experimental evidence shows it can be, this is a very efficient 
method of treatment in infectious fevers. Spinal manipulation, 
which produces free movement between the vertebrae named, 
should be continued for ten or fifteen minutes at each treatment 
and several such treatments given daily during the febrile state. 

Dr. McConnell has shown that bony lesions of the mid-dorsal 
and lower dorsal regions are followed by pathological lesions of 
the kidney, and Dr. Burns has shown that lesions of the eleventh 
and twelfth thoracic produce vaso-dilation of the vessels of the 
kidneys. 



CHAPTER LXII. 
SERIES NO.*17. 

OSTEOPATHIC STIMULATION OF BILE-FLOW. 

Geo. D. Scott and H. A. Wendorff. 

This is the record of a series of experiments undertaken at 
the instance of" Dr. J. Deason in the laboratories of the American 
School of Osteopathy to ascertain whether or not the physician 
can in any way influence the flow, of bile. As will be seen, the 
results were most gratifying. Carefully tabulated records were 
kept of the findings, but as the whole series of tables would occupy 
an undue amount of space, it is deemed best to give only the 
results obtained in each case, and to group them all in one table. 

Methods and Technique. — Dogs were the only animals 
used; the technique was extremely difficult and tedious, but 
great care was taken to assure that the results obtained were 
exactly accurate in each case. 

All dogs were put under complete anesthesia by means of 
ether given by tracheal cannulse. The animal was tied onto a 
table of small size kept for the purpose, and an incision made in 
the abdomen, extending from the xiphoid toward the symphysis. 
The operator then passed his hand into the abdominal cavity, 
grasped the common bile duct and pancreatic duct and other 
structures thereto attached, and after closing off the bile duct 
by means of a "bulldog," it was cannulated at a point above its 
junction with the pancreatic duct. 

Many peculiarities of structure were found in different ani- 
mals, and the operators were obliged to lose many dogs without 
even getting the duct cannulated. One animal had a bilateral 
liver, and the common bile duct was divided up into so many 

565 



566 physiology: 

smaller ducts that nothing could be done. This is only one illus- 
tration of the difficulties met with. In fact, a lengthy article 
could be written on the abnormalities of structure found in many 
of the animals opened. 

After cannulating the duct and inspecting the gall-bladder 
to see that it was normal and to ascertain the approximate content, 
the " bulldog" was removed, the edges of the skin brought together 
and fastened, the right limbs untied from the table, and the ani- 
mal turned onto the left side. 

Stimulation was effected by rotation of the seventh to ninth 
dorsal vertebrae, but mostly the eighth, as follows: The operator 
stood at the animal's back and, in order that there might be no 
compression on the abdominal cavity, thus influencing the flow 
of bile, grasped the dog's right foreleg in the left hand and with 
the right rotated the vertebrae by means of the spinous processes. 
At the close of each experiment the gall bladder was again examined 
and in every case found to contain as much bile as at the beginning 
with one or two exceptions, when a perceptible increase was present. 

Normal Flow Flow after 

flow in in 15 min. stim. ended 

15 min. stim. mid- drops 

drops. dorsal. 15 min, 

Dog No. 1 55 72 30.9% inc. 68 

Dog No. 2... 41 78 , 90.2% inc. 74 

Dog No. 3 46 69 50 % inc. 65 

Dog No. 4 57 76 31.5% inc. 67 

Dog No. 5 52 74 42.3% inc. 69 

Dog No. 6 45 81 80 % inc. 75 

Average 49 75 53 % inc. 69 .6 

As will be seen from the above table, the normal rate of 
flow was taken before stimulation was started and again after 
stimulation ceased, and the increase in flow from the manipulation 
continued for some time afterward, though not at the same rate. 
In one or two cases by count, the increase was noted for as long 
as half an hour, it gradually receding toward the normal. 

Some animals, other than those from which results are tabu- 
lated above, were prepared in the usual way and "spondylo- 
therapy" attempted by percussing the spines of the vertebrae 



GENERAL AND OSTEOPATHIC. 567 

in the same region as stated above, but in not a single instance 
was there an increase in the bile-flow, and the experiments were 
abandoned. Five dogs were used in this way. The carotid 
artery and trachea were attached to the kymograph, but not 
the least variation in either blood pressure or respiration occurred 
during the percussion. 



CHAPTER LXIII. 

PERVERTED PHYSIOLOGICAL EFFECTS AS A 
RESULT OF OSTEOPATHIC LESIONS. 

From the evidence which has been offered in the foregoing 
pages in the second part of this book, it may be seen that we have 
arrived at no hasty conclusion in stating quite positively that 
we know that those structural perversions which have so long 
been recognized and known as osteopathic lesions are productive 
of functional perversions, which are detrimental to the well-being 
of the animal. Instead of hastily concluding, we have on the 
other hand progressed slowly, step by step, and have offered un- 
deniable experimental evidence of the relations of these structural 
perversions to the abnormal physiological and pathological condi- 
tions of which they are known to be the cause. 

The clinical side of the evidence is of course not to be found 
in this book, but ample osteopathic literature may be had dealing 
with this phase of the subject, and this, the clinical evidence, 
has done far more in the past to turn people towards osteopathy 
as a method of healing than has the experimental evidence. 
Realizing this fact, as we do, and after having had a few years 
of experience in the application of these principles to many differ- 
ent clinical conditions (mostly the acute infectious fevers) and 
after having worked several years at original experimental re- 
search, we believe we have a right to express an opinion and that 
opinion is that osteopathic methods of therapy are scientifically 
sound, both theoretically and practically. 

It is no longer a question as to whether the bony lesion is 

causative of perverted physiological and pathological effects, 

for this has many times been demonstrated by the finding of bony 

lesions so constantly in association with the clinical conditions, 

568 



GENERAL AND OSTEOPATHIC. 569 

and the fact that many different experimenters have conclusively 
shown that the production of " artificial bony lesions" in normal 
animals is followed by clinical conditions and demonstrable patho- 
logical changes comparable to those conditions found in human 
individuals. It is not any longer a question as to whether the 
correction of these bony lesions is conducive to the normalization 
of the perverted physiological conditions, for this has been answered 
in the affirmative by the results of the most excellent work 
of those earnest physicians whose trained brains and hands have 
done the correcting of such lesions in human individuals and by 
the results of original experimentation, which has shown that 
the correction of the " artificial bony lesion" in animals will be 
followed by a relief of the symptoms which their existence had 
produced. 

The question now for osteopathic physicians is: "What 
is the method by means of which the bony lesion causes these 
disturbances?" This once answered, we may be better able to 
reason from cause to effect and apply our treatment accordingly. 
In the following pages of this chapter we will briefly discuss the 
different theories which have been offered for the explanation 
of the mechanism by means of which these effects are produced. 

Direct Pressure on Nerve Trunks. — This theory main- 
tained that the effects from bony lesions occurred as the heading 
suggests, from direct pressure upon the nerve trunks by immediate 
impingement. Such explanations seem improbable, because 
from a knowledge of the anatomical relations of the vertebral 
segments, such a direct impingement of the nerve trunks would 
seem improbable, at least, if not impossible. There are some 
conditions in which direct pressure effects might account for these 
results, such for example as in case of lesion of the sacro-iliac 
synchondroses and probably in some other instances, direct pres- 
sure effects may account for the physiological perversion by direct 
traumatism, either by pressure or stretching effected upon the 
nerve trunk. In such cases the effects at first would probably 
be a stimulation to the structure supplied by the efferent fibers 
in the nerve trunk and reflex effects causing increased activity 



570 PHYSIOLOGY : 

of the centers in the cord lying in immediate or near relation 
with the afferent fibers which enter the cord from these nerve 
trunks. By this means it would be possible to explain many so- 
called reflex effects which are known to result from bony lesions. 

By far the greater part of the better osteopathic authorities 
is not and has never been in favor of such an explanation of the 
effects of bony lesions. We do not know of any case where 
the results of original osteopathic research would bear out the 
ideas of this theory except in a few rare instances, as explained 
above. In cases where artificial lesions have been produced 
in animals for the study of the results the dissection of the struc- 
tures after the lesion had been produced has, so far as we are 
able to determine, never shown that there was any direct impinge- 
ment upon the nerve trunks. 

Reflex Effects. — This theory has been advanced, the prin- 
ciple of which is that excessive stimulation of the afferent fibers 
caused by a strain in or about the joint segments involved in the 
lesion, which in turn causes reflexly a greater amount of stimulation 
in the synaptic part of the cord and, therefore, a greater amount 
of efferent stimulation by way of the nerve fibers (somatic and 
splanchnic efferents) extending from cell bodies in the anterior 
and antero-lateral part of the gray matter of the spinal cord. 

As evidence of this explanation we offer the following: 1. 
It has been shown experimentally by Dr. McConnell that osteo- 
pathic lesions produced in normal animals cause pathological 
changes in the afferent fibers of the spinal nerves and in the affer- 
ent columns of the cord. Such conditions would of course influ- 
ence the normal reflexes and on long standing impair the functions 
of structures supplied by efferent fibers from the involved seg- 
ments by reducing their tone, trophism, vasomotor supply, etc.; 
2. It has also been shown experimentally by Dr. Burns that 
lesions produced in normal animals and in the human cause im- 
mediate reflex effects characterized by marked perverted physio- 
logical functions such as excessive secretion, abnormal vaso- 
motor control, etc.; (See Dr. Burns' chapter on reflexes.) 3. 
In our research work it has been shown that bony lesions produced 



GENERAL AND OSTEOPATHIC. 571 

in normal animals cause many reflex effects, e. g., abnormal move- 
ments of the stomach and intestines (see Series 5 and 9), abnormal 
functions of the heart and blood vessels, and other perverted 
conditions (see Series 10). 

The results of observations of many physicians in their clinical 
practice also bear out the statement that osteopathic lesions 
produce a great variety of symptoms which may usually be re- 
lieved by the correction of the structural perversion. In order 
that the effects of the osteopathic lesion on the reflexes may be 
better understood the relation of the lesion to the synaptic nervous 
system should be carefully considered, since this system is in- 
volved in all reflex actions. 

Involvement of the Synaptic Nervous System. — The 
reader is urged to review the physiology of this system, that he 
may be better able to understand the principles involved. (See 
text, page 272, Part I, and Series No. 10, Part II.) The term 
synaptic nervous system has been applied to those intermediate 
fibers which lie principally in the gray matter of the cord and brain 
and which constitute the connection between the afferent and 
efferent neurones and complete the reflex arc. The term 
"synapse" is applied to the connections which exist between the 
afferent and efferent fibers. (See page 272.) To understand 
the physiology of this connecting mechanism we must consider 
that these interconnecting neurones, the commissural and asso- 
ciation neurones, constitute actual living cells and, as we have 
quoted from Sherrington before, " nerve cells, like all other cells, 
lead individual lives — they breathe, they assimilate, they dis- 
pense their own stores of energy, they repair their own substan- 
tial waste ; each is, in short, a living unit, with its nutrition more 
or less centered in itself. Here, then, problems of nutrition, 
regarding each nerve-cell and regarding the nervous system as a 
whole, arise comparable with those presented by all other living 
cells. Although no doubt partly special to this specially differ- 
entiated form of cell life, these problems are in general accessible 
to the same methods as apply to the study of nutrition in other 
cells and tissues and in the body as a whole. " 



572 physiology : 

We see, therefore, in this mechanism a highly differentiated 
structure whose functions are accurately adjusted for the per- 
formance of a highly specialized function. "At each synapse a 
small quantity of energy, freed in transmission, acts as a releasing 
force to a fresh store of energy not along a homogeneous train of 
conducting material as in a nerve-fiber pure and simple, but across 
a barrier which, whether lower or higher, is always to some extent 
a barrier. " (Sherrington.) The synaptic part of the reflex arc 
is actually the functional key to the entire reflex system, and any 
failure in its function certainly means far reaching perversions 
of function. 

That the osteopathic lesions produced in normal animals 
affect the functions of the synaptic system has been shown in 
Series 9 and 10. That these effects are not due to spinal shock 
we cite the reader to the evidence offered in Series 10. After 
the production of the lesion in normal animals the reflexes are 
diminished and the tone of the structures supplied by efferent 
fibers from the affected segments is reduced. In several of our 
different series of experimental work we have* successively noted 
that the lesion produced artificially in normal animals is followed 
by reflex disturbances somewhat comparable to reflex inhibition, 
but differing from physiological reflex inhibition in that the effects 
are much more marked and are of greater duration. Since there 
is evidence that the synaptic nervous system is involved as a 
result of the osteopathic lesion an explanation of the probable 
causes of such effects seems to be in order, which we believe is 
answered in the following paragraphs. 

Congestion of the Segments of the Spinal Cord. — 
Several research workers have found that congestion of the spinal 
cord occurs following artificial bony lesions, which may affect 
only a few or several segments of the cord, according to the nature 
of the lesion produced. We have confirmed these findings in 
our experimental work and believe the greatest amount of con- 
gestion occurs in animals in most cases very soon (five to twenty 
minutes) after the production of the lesion. (It would seem that 
the same condition ought to be present in the human following 



GENERAL AND OSTEOPATHIC. 573 

acute bony lesion from any cause.) In some cases this congestion 
clears away and the opposite, an anemic condition, results, while 
in other instances the congestion persists. 

During the period of congestion we have found that the 
resistance in the synaptic system is greatly increased. If, for 
example, as shown in Series No. 10, the central end of some affer- 
ent or mixed nerve be stimulated reflex effects, e. g., increased 
heart rate, increased respiration, etc., result. Now, if an arti- 
ficial bony lesion be produced in the mid-dorsal region and the 
experiment repeated, it will be found that the stimulation of 
afferent or mixed nerves which enter the cord below the point 
of lesion is not followed by an increase in these functions, while 
on the other hand stimulation of afferent or mixed nerves which 
enter the cord above the point of lesion do produce an increase in 
these functions just the same as the stimulation of all nerves be- 
fore the lesion was produced. If the lesion be produced in such a 
way as to involve all of the segments of the cord from which effer- 
ent fibers arise supplying a certain structure, this structure is 
not normally affected reflexly by the stimulation of any sensory 
fibers, whether they enter the cord above, at, or below the area 
from which the structure is supplied. This evidence would seem 
to show that the congestion surely increases the resistance of the 
synaptic nervous system or builds a " barrier" preventing the 
transmission of the impulses from the afferent to the efferent 
conductor. As further evidence of this fact we have found that 
this marked increased resistance is of comparatively short dura- 
tion, for from ten to twenty minutes after the production of the 
lesion the reflex functions begin to return to normal unless the 
lesion is a permanent one, in which case the return to normal 
is markedly delayed. This return of the normal reflex functions 
would seem to be due to the relief of the congested condition of 
the segments of the cord involved, and a careful examination has 
tended to confirm this view. 

"The living cell is constantly liberating energy in its func- 
tion, and rebuilding its complex structure from nutrient material. 
Its life is therefore an equilibrium of balanced katabolism and 



574 physiology: 

anabolism ; at any given moment the one process or the other 
may predominate in the cell." (Sherrington.) Since this is 
known to be true and since the " nerve cells like other cells lead 
individual lives/' etc., and since these cells demand their normal 
quota of normal blood, any condition varying this function must 
certainly affect the functions of these cells. Now because the 
synaptic system of neurones is necessarily so easily influenced, 
it follows that this system would be one of the first to be affected 
by such lesions. We believe, as Dr. A. B. Clark states, that 
"Dr. Still never spoke the truth more perfectly than when he 
said 'The rule of the artery is supreme','' because it is the blood 
supply to the nerve cells which furnishes the energy for the normal 
functional activity of nerve cells, just the same as normal nutri- 
tion is demanded for the function of all other cells. (See Source of 
Nerve Energy, pp. 305 and 280.) 

The excess of blood to the part is not the only and, we believe, 
not the chief cause of the lack of normal function of the nerve 
cells in the cord. It has been pointed out elsewhere that the 
venous drainage from the cord must be normal in order that the 
cord functions may be normal, as the retention of end products 
of metabolism, such as C0 2 , etc., must be promptly removed 
that the functions of the nerve cells in the cord may be normally 
maintained. This factor, the retarded drainage of the blood 
from the cord, is,- we believe, the factor which has most to do 
with the production of the lasting effects of osteopathic lesions. 
Anything, then, which interferes with the drainage of the blood 
or lymph from the cord must surely influence these functions. 
Dr. McConnell has repeatedly shown that reflexly the drainage 
from the cord and surrounding tissues is affected by artificial 
bony lesions. It is probable that the blood supply to the cord 
is influenced reflexly through the vasomotors as a result of bony 
lesions. The results of experimental work bear out this state- 
ment. 

It does not seem probable that direct pressure on the arteries 
supplying the cord is a very probable explanation for these causes, 
for reasons previously stated. It may be that pressure causing 



GENERAL AND OSTEOPATHIC. 575 

by congestion a proliferation of adjacent tissue does to some 
extent interfere with the drainage through the thin-walled veins 
and lymphatics, but it also seems probable that a loss of tone 
to the arteries causing excessive dilatation of these structures 
caused by the effects of the lesion would cause an excess of blood 
to the part; more, in fact, than could be drained away, and thus 
a more permanent congestion would follow than would be caused 
by the reflex effects alone. 

By Affecting the General Integrity of the Central and 
Autonomic Nervous Systems. — It has been stated in Part I 
that there are two general ways (the integrative function of the 
nervous system and the circulation of internal secretions) in which 
the unification of all body functions is maintained, and it has 
been shown how the interrelations of the different parts of the 
nervous system and the formation, circulation, and activity of 
the internal secretions bring about this co-ordination of the various 
body functions. That all of the different structures of the body 
bear certain functional relations and that these relations are 
activated and maintained by these two functional systems is now 
well understood. It is equally well known that unless this func- 
tional relationship is maintained that the animal body as a whole 
cannot perform its normal function, and that a condition of 
uniform body health cannot exist. We believe that it is a 
common error of physiologists and physicians to overlook this 
most important physiological fact. 

It has been shown many times and by different research 
workers that the osteopathic lesion when produced artificially 
in normal animals affects many and varied changes reflexly, 
which alter the functions of different structures. It has been 
shown how osteopathic lesions may interfere with. the sjmaptic 
system and in fact may involve the entire reflex mechanism, 
thus preventing the integrative fun'ction of the nervous system, 
from co-ordinating the functions of the various structures. To 
show the interrelation existing between these two systems we 
quote the following: "This synaptic system co-existing with the 
diffuse in various places dominates the latter. Thus it controls 



576 physiology: 

and oversees the actions of the local nervous system of the viscera, 
and heart, and blood-vessels, which even in the highest animal 
forms remain diffuse. 

"The synaptic nervous system has developed as its distinc- 
tive feature a central organ, a so-called central nervous system; 
it is through this that it brings into rapport one with another 
widely distant organs of the body, including the various portions 
of the diffuse nervous system itself." (Sherrington.) 

Such perverted functions as (1) impaired regulation of the 
vasomotor system; (2) impaired secretion of different glands, in 
some cases the secretion is increased and in other instances dimin- 
ished; (3) perverted metabolism; (4) decreased function of certain 
organs of internal secretion; (5) decreased trophic functions, 
and many others have been observed both experimentally and 
clinically from the effects of osteopathic lesions. 

The lesion, then, by its interference with the normal func- 
tions of the nervous system may cause in the different ways ex- 
plained above many perverted physiological conditions which 
reduce the normal body resistance and interfere with the normal 
unity of function of the different organs, which is so essential to 
health. In considering this function of the nervous system as a 
regulator of the various body functions Sherrington most inter- 
estingly observes that "An actual living internal bond is devel- 
oped. When the animal body reaches some degree of multi- 
cellular complexity, special cells assume the express office of 
connecting together other cells. * * * And we find this living 
bond the one employed where, as said above, speed and nicety 
of time adjustment are required, as in animal movements, and 
also where nicety of spatial adjustment is essential, as also in 
animal movements. It is in view of this interconnecting function 
of the nervous system that that field of study of nervous reactions 
which was called at the outset the third or integrative, assumes 
its due importance. The due activity of the interconnection 
resolves itself into the co-ordination of the parts of the animal 
mechanism by reflex action." 



GENERAL AND OSTEOPATHIC. 577 

The effects of the bony lesion upon this integrative function 
of the nervous system is a most important physiological and clini- 
cal problem. We believe this theory serves to explain the cause 
of a great many clinical conditions classed by medical physicians 
as idiopathic because they have no means of determining the 
cause. 

It seems equally probable that many osteopathic physicians 
may make the same error because an osteopathic lesion sufficient 
to cause effects of this kind may be only very slight and difficult 
of detection. Osteopathic lesions in this way may produce their 
effects slowly, the results being a gradual decrease in the normal 
resistance of the individual until some secondary cause like bac- 
terial infection hastens the process. Thus we have the so-called 
predispositions of certain individuals to the various infectious 
and other disease conditions. 

By Causing Hyperirritation of the Nervous System. — 
That osteopathic lesions are frequently causative factors of con- 
ditions of hyperirritability has been observed by clinicians and 
research workers. Animals after lesioning often become very 
noticeably nervous and many, if not all osteopathic practitioners 
have observed that bony lesions may be the cause of nervousness 
which can usually be relieved by the correction of the lesion. 
The effects in such cases may be due to an excessive stimulation 
of the afferent system and the spasmodic nature of the condition 
may be due to a " summation of stimuli" and an increased re- 
sistance of the synaptic system which now and then gives rise 
to a flood of afferent stimuli passing to the efferent system, which 
may be the cause of such effects. 

The effects of lesions causing such irritability are varied. 
The effects may involve the entire system, causing general nerv- 
ousness; it may affect some one structure or group of structures, 
increasing or inhibiting their functions, or it may only influence 
the general integrity of the entire system. 

Conclusion. — In the various ways, as stated in the pre- 
ceding pages, and possibly in other ways osteopathic lesions have 
been shown to produce physiological perversions. We have 



578 PHYSIOLOGY : 

considered for the most part the different ways by means of which 
the osteopathic lesion may produce immediate effects. These 
conditions if long continued would result in permanent effects. 
As evidence of this fact we refer the reader to the work of Dr. 
McConnell, who has many times shown that pathological changes 
result from permanent bony lesions. We have confirmed these 
results and have further shown that lesioned animals when kept 
for long periods of time show constantly increasing physiological 
abnormalities. 



CHAPTER LXIV. 
INNOMINATE LESIONS. 

By F. P. Millard, D. 0., Toronto, Canada. 

Clinically speaking, innominate lesions have been known to 
exist, and have been therapeutically corrected since osteopathy's 
innovation. The position of the innominate bones is such that 
lesions, however slight, are significant and have naturally at- 
tracted the attention of our physiciajis from the earliest osteo- 
pathic days. Until recently a great many clinical experiments 
have remained unverified from the fact that our research work 
has been limited. However, it is pleasing to know that some of 
our best doctors have been delving into this particular lesion 
proposition from a research standpoint, and although the reports 
have not been given out, I am in a position to know that some 
splendid work has already been done by our worthy research 
workers, Drs. Deason and McConnell. 

We cannot be too accurate. We have always appealed to 
the people from a scientific standpoint. We have constantly 
made statements that the workings of the human anatomy were 
to be referred to on a mechanical basis. Clinical experiments 
have apparently demonstrated a great many wonderful features. 
We have longed to verify these reports with accurate and absolute 
proofs. In a general way I am going to refer to some of the 
experiments which have been made and which are to be continued 
at an early date. The innominate lesion is vital in relation to the 
physiological functionings of the human anatomy. Lesions of this 
nature are not necessarily direct in their workings, but are in a 
great part, at least, reflex through the various nerve connections 
which exist in this section of the anatomy. 

579 



580 PHYSIOLOGY : 

Referring to the work that Dr. Deason has been conducting 
and the various specimens forwarded to Chicago and passed upon 
by Dr. McConnell, we have this to say: The pathology, while 
slight, was definite. The medullary sheaths showed a beginning 
of parenchymatous degeneration in the upper and lower sciatic 
sections. Changes were more pronounced in the nerve groups 
just outside the spinal cord. Slight passive congestion existed 
in the sciatic nerve, but no special lesion of the artery could be 
made out. This, in a general way, is the report of the findings 
from a research standpoint. 

During the experimental stage at Kirksville the innominate 
lesions showed these points: no paralysis, peristaltic action 
increased, moderate glycosuria varying from one-tenth per cent 
to seventy-five hundredths per cent lasted from one to five or 
six days in some cases. The urinary findings showed increase 
in albumen a few days after the lesion and an increase in chlorides 
in one case. With no particular change in the specific gravity 
nor urea, qualitative and quantitative analyses were made in 
all of the cases before and after the lesions produced. A post- 
mortem examination found that the subluxations were sufficient 
to justify the name lesion and produce the pressure and changes 
which would correspond with an innominate lesion in a typical 
case. 

The sacro-iliac articulation is a true synchondrosis. Hulett's 
reference of a few years back, "Bear in mind the fact that the 
sacro-iliac articulation is an arthrodial or gliding joint, and in 
many younger individuals is supplied with the typical structures 
including the synovial membrane and fluid. This suggests a 
fair degree of movement, " etc., coincides with that of Goldthwaite 
in his " Diseases of the Bones and Joints/' in which he states: 
"This of course impairs the normal function of the joint, and 
because of the character of the articulations in the pelvic girdle, 
it is evident that if one joint is injured each of the other joints 
must be somewhat strained, so that the disability resulting from 
even a slight luxation of one of the sacro-iliac joints may become 
very great." * * * "In any disease of the pelvic organs in which 




Plate XXXVI.— Side view of the innominate in its normal po- 
sition in relation to the sacrum. The dotted lines indicate the 
directions in which this bone is most likely to be misplaced. The 
line A. B. is used for diagnotsic purposes, passing as it does through 
the center of the acetabulum and the superior anterior spine and the 
tuberosity of the ischium. 

(Through an error in interpreting instructions our engravers made 
this cut smaller than the following two. — Ed. 






GENERAL AND OSTEOPATHIC. 581 

there is large circulatory disturbance the joints become relaxed, 
as a part of the same physiological reflex noted in pregnancy and 
menstruation. While this is probably true, the converse is also 
certainly true; namely, that if the pelvic joints become relaxed 
as the result of accident or disease, the lack of stability of the 
pelvic girdle, with the resultant weakening of the support of the 
pelvic organs, leads to congestive disturbances in these organs, 
this in turn probably acting upon the joints, so that until the 
proper treatment can be instituted there exists a vicious circle 
of cause and effect." "The bone surfaces are smooth and slightly 
irregular, so that the stability of the joint depends almost entirely 
upon the ligaments and muscles. This being the case, anything 
that leads to the loss in the muscular or ligamentous tone renders 
the joints more prone to strain, and as their stability depends 
upon soft structures, disturbances in the normal approximations 
in the bones must be more common and result from less violence 
than in the other joints." 

Some years ago Dr. Hazzard made some interesting clinical 
experiments, illustrating the same, with, I believe, the first dia- 
grams showing a slipped innominate. He stated "that bony and 
ligamentous lesions of the pelvis, so significant from the osteo- 
pathic standpoint, are causes of disease in the pelvic viscera, in 
the limbs or in the body above, " and that "the general symptoms 
of said troubles are pelvic diseases, female disorders, backaches, 
neck lesions, sciatica, lameness or paralysis of the lower limbs, 
etc." Research experiments carried out by Deason and Mc- 
Connell have demonstrated the accuracy of his prophetic state- 
ments. 

Goldthwaite makes the statement that in injuries not only 
are the joint structures injured or strained, but the large nerve 
trunks which cross this articulation in front are frequently irritated. 
"Anatomically the sacral plexus of nerves with some of the branches 
from the lumbar plexus cross just in front of the synchondrosis. 
This being the case, it is not difficult to understand the fact that 
irritation of these nerves is possible." Deason's experiment 
does not confirm this statement, although further experiments 



582 physiology: 

may prove in some long standing case that deposits exist which 
interfere with the tonicity of these nerve cords in their relation 
to the sacro-iliac joint near the promontory of the sacrum. 

Deason says: "What, for example, is the explanation of 
the extreme nervousness, menstrual disorders, intestinal disturb- 
ances, etc., which so often follow so soon after a slight lesion of 
the innominate has occurred, and which has neither increased 
nor involved other pelvic joints? That such conditions may 
exist we have shown by experiment. We believe the explanation 
in such cases is this : That reflex effects, involving certain viscera, 
as has been mentioned could result from the stimulation of some 
afferent or mixed nerve by pressure or otherwise, we can say that 
the theory, at least, seems tenable when we recall that such re- 
flexes have many times been demonstrated. Many of these 
reflexes are furthermore specific in action, such, for example, as 
the contraction of the uterus from mechanical stimulation to the 
perineum or direct stimulation of certain sacro-spinal nerves." 
S chafer states that "In animals such contractions are strongly 
excited by faradization of the central end of the first sacral nerve. 
As the excitation in these instances is not applied to the uterine 
tissue or to afferent nerve channels, the resultant uterine reactions 
must be induced reflexly. " 

The research work so far has at least shown a perverted physio- 
logical condition affecting the splanchnic region as well as the 
renal. This ends our comment on the experimental work, which 
we hope will soon be completed by those who are working to that 
end. 

The innominate bones form the greater part of the boundaries 
of the pelvic cavity and hence have the greatest ligamentous 
and muscular attachments, containing at the same time the thigh- 
bone sockets. From the upper border of the innominates arise 
the largest muscles in the back, extending as far as the skull in 
some instances. From these same bones the ensheathing muscles 
of the thigh arise, and in relation to these innominates pass some 
of the largest blood vessels and nerve trunks in the human body. 
Within the basin whose walls are formed by the innominates, in 
particular, lie some of the most delicate structures and tissues. 




^••••« 



Plate XXXVII. — Shows the anterior view of the pelvis with the innominate in normal 
position. A. B. is the transverse axis upon which the innominate turns when subluxated. 
The dotted lines indicate the different positions which the innominate would be most likely to 






i, 



;4 



GENERAL AND OSTEOPATHIC. 583 

The weight of the body and its burdens falls upon the sacrum, 
which is wedged between the innominate bones in an oblique 
position, necessitating great ligamentous and muscular counter- 
acting forces. It is the close proximity of the nerves and vascular 
tissue of the sacro-iliac joints, bound down as they are by fascia 
and connective tissue, that has concerned us in cases of rheuma- 
tism in which the possibility of a lesion at the sacro-iliac joint may 
thicken the tissues and possibly leave a deep-seated deposit, 
referred to already in this article. It is impossible to change 
the position of the sacrum and not disturb the integrity of the 
pelvic basin itself. If the sacrum is rotated in any direction the 
innominates are changed in their relation to this bone, and when 
the innomtnates are twisted the ligaments and muscles attached 
to them are likewise altered. Again, when the ligaments and 
muscles are put upon a tension or .unduly relaxed the vascular 
and nervous tissues are deranged, and when innervation and 
vascularity are abnormal the organs and tissues supplied likewise 
suffer, and reflexly adj acent organs are usually involved. Although 
a sacral rotation may seem simple, yet a joint disturbance may 
be the outcome through a reflex chain of reasoning just referred to. 

From a mechanical standpoint the pelvis is one of the most 
intricate pieces of mechanism in the human anatomy. Imagine 
the muscular and ligamentous tension placed upon the pelvic 
tissues when burdens are being carried. Irregularities of the 
pelvis do not constitute lesions unless associated with tenderness 
and disturbance of function of the articulations or associated 
viscera. Lesions in pelvic disorders may include not only those 
of the pelvic construction, but subluxations or partial displace- 
ments of the last rib, and the lower dorsal, as well as the lumbar 
vertebrae. Reasoning from an anatomical standpoint, disturbed 
function may follow mal-alignment of the lower dorsal region, 
as such a lesion may irritate the deep origin of the sciatic and 
pudic nerves and possibly the lumbar and sacral nerves. We 
must remember that the pudic nerve arises from cord segments, 
on a level with the twelfth dorsal to the first lumbar vertebrae. 
Remember the cord terminates at the upper border of the second 



584 physiology: 

lumbar vertebra. If the origin of the lumbar and sacral nerves 
is above the point of spinal-cord termination, a lesion in the lower 
dorsal must directly or indirectly affect the nerves just mentioned. 
These nerves have a controlling influence over the pelvic organs 
and tissues. The lower dorsal lesions affect the general nutrition 
of the cord, as well as the blood supply to the particular segment. 
It is quite improbable that a lesion would exert pressure sufficiently 
to affect the nerve trunks directly, as paralysis would naturally 
ensue, but subluxations could be of sufficient significance to affect 
the nutrition and vascular supply of the cord and its branches, 
disturb the venous drainage which is conveyed by way of the 
intercostal, lumbar, and pelvic veins. However slight the sub- 
luxation, vascular irregularities will follow until complete reduc- 
tion of the lesion is made. If contracted muscles exist venous 
stasis is most likely present, and as the vessels in the deep muscles 
are closely connected with those of the vertebral, as well as the 
cord segments, it is easy to understand the importance of correcting 
and adjusting the slightest abnormalities. 

If venous stasis exists in the spinal cord vessels for any period 
of time degeneration of the cells must take place, and if the lesion 
is of sufficient importance to disturb the posterior root ganglion, 
the impingement must be removed or pathological conditions 
will follow. Should the rami communicantes in any way become 
involved the connecting link between the spinal and sympathetic 
system becomes interfered with, and the reflex actions are lost. 

The pudic nerve supplies so many pelvic organs and tissues 
and its origin is so high that there must be perfect nutrition and 
complete freedom from irritation and congestion to insure the 
passing of normal impulses. The position as well as the functionings 
of the pelvic organs depend greatly on the density of the pelvic- 
floor tissues. If lack of tone exists a disarrangement may take 
place in the way of misplacements, congested areas, adhesions, 
etc. This may be due to visceral ptosis, but more often it is the 
result of faulty innervation induced by improper nourishment 
of the nerve trunks and tissues. Back of all this disturbance a 
slipped innominate may have been the primary cause. 




Plate XXXVIII. — Posterior view of the pelvis in its normal relationship to the sacrum. 
The dotted lines show the innominate twisted forward and backward on its transverse axis in 
relation to the sacrum. 



GENERAL AND OSTEOPATHIC. 585 

Whenever the lower thoracic region is under consideration 
we must not forget the rib attached thereto. The eleventh 
and twelfth ribs are frequently found in lesion, possibly through 
tight lacing or faulty position, but usually the result of scoliotic 
conditions. These costal lesions cause disturbances in the rami, 
producing trouble in renal and ovarian plexuses. As the ganglia 
of the sympathetic cord lie in such close relationship to the heads 
of the ribs, and as these two ribs are floating and have no anterior 
support other than muscular, displacement is easy and disturbance 
of the sympathetic ganglia is common. The return vascular flow 
from the pelvic organs may be checked somewhat by a subluxation 
of the lower ribs which constrict to a certain extent the vascular 
openings in the "diaphragm. This may be of sufficient import 
to produce congestion in part or all of the pelvic organs, but it 
will depend entirely on the manner ajid extent to which the ribs 
are subluxated. 

Lumbar lesions are so common in cases of pelvic troubles 
that we naturally look for vasomotor and trophic changes through 
disturbance of the sympathetics. The ganglia lie in front of the 
bodies of the vertebra? in this region, and are connected with the 
lumbar nerves and plexuses, as well as the lumbo-sacral cord 
through the rami communicantes. These ganglia supply plexuses 
to the various arterial branches of the abdominal aorta, such as 
the inferior mesenteric, ovarian, branches to the uterus, tubes, 
etc. The lower portion of the colon, including the sigmoid, 
receives nerve filaments from this same source, making possible 
a variety of complications to the bowels as well as the tubes and 
ovaries. Whenever we find two or more organs supplied by 
nerves from practically the same source we may look for complica- 
tions of troubles. 

The sympathetic ganglionic chain sends branches to the 
hypogastric plexus, and disturbance to this plexus may also be 
caused by lumbar lesions, as it is located near the promontory 
of the sacrum adjacent to the fifth lumbar. Taken as a whole, 
the lumbar region is of great importance, and the lumbar enlarge- 
ment of the cord contains centers for most of the pelvic organs. 
The pelvis normally is bound together with firm, ligamentous 



586 physiology: 

bands, draped internally with fascia and muscles, which folds 
are perfect according to nature's intention. Suspended within 
this basin are the pelvic organs with ligamentous tension equal 
on all sides, and muscular supports as well. Misalignments, 
however slight, produce tension on certain of these on the one 
hand, and vascular inadequacy on the other. Resultant com- 
plications are inevitable. No mechanism will work in perfect 
harmony if friction exists, or if distortion be present. The toxic 
condition of the bowels, due to faulty innervation or vascular 
irregularities through lesions or structural defects, invariably 
causes disorder in proportion to the severity of the lesion. In 
order that the normal function may exist and continue, organs 
and nerves must not be impinged upon and vascular freedom must 
be present. The vasomotors must be in perfect working order as 
well as the tissues in which the blood vessels are imbedded. 

The vasomotor centers controlling the circulation of the 
uterus are located in the lumbar region. A rigid spine, a curvature, 
or a specific lesion will affect these centers. As before mentioned, 
the hypogastric plexus is situated at an extremely important 
point, helping as it does to form the pelvic plexuses, which are 
made up principally from the upper sacral ganglia, the second, 
third and fourth sacral nerves. These plexuses serve as switching 
stations for almost as many impulses as does the solar plexus, 
and control chiefly the various pelvic functions such as secretions, 
absorption, ovulation, uterine peristalsis, menstruation, gestation, 
etc. This plexus also furnishes vasomotor fibers to the pelvic organs. 

Regarding visceral ptosis, not only pelvic misplacements are 
the result, but the blood supply of that region is disturbed and 
venous and lymphatic stasis ensues. A foundation is thus laid 
and material furnished for tumors and various growths. The 
arteries are usually capable of expansion under ordinary circum- 
stances. Any great interference or resistance may produce 
aneurism. The venous circulation, on the other hand, has less 
propelling power, and the veins are more readily engorged. In 
such a case the arterial flow is undisturbed and the new growths 
are the result of tumefaction from the disturbed lymph and blood 
channels. 



INDEX. 



Absorption in the intestines, 164 
Accommodation, mechanism of, 369 
Accessory foods, 199 
Adrenal bodies, 219 
Air pressure in thorax, 115-118 
Alcohol, 200 

Alimentary canal, from an osteo- 
pathic standpoint, 177 

spinchter valves of, 175 
Altitude, effects of on respiration, 131 
Amboceptors, 26 
Anacrotic limb, 86 
Antibodies, 26 
Antithrombin, 33 
Aphasia, 327 

Artificial respiration, methods of pro- 
ducing, 113, 114 
Atropin, 59 
Auditory sensations, 354 

course of, 356 - 
Autonomics, cranial, 76 
Autonomic nerves to heart, 55-63 

to blood vessels, 64-77 

Bacteria and phagocytosis, 29 
Bacteriolysins, 29 
Bell-Magendie law, 266 
Bile, constituents of, 158 

secretion of, 159 
Bladder, structure and function of, 185 

nerve supply to, 185 
Blood, 19 

chemical properties of, 31 

clot, 33 

coagulation, 32 

constituents of, 21 

corpuscles of, 21 

corpuscles, white, 27 

distribution, 38 

effects of bony lesions on forma- 
tion of, 453 

letting, 37 

of neurasthenics, 456 

plasma, 21 

plates, 30 

properties of, 20 

proteins, 31 

serum, 21 
Blood cells, Burns' researches on, 
447-461 

Blood pressure, 80 

conditions causing variation in, 

92 
effects of respiration on, 120 
methods of study of, 80 
normal, 84 
systolic and diastoltic variation 

of, 82 
variations in, 84 



Blood flow, velocity of, 78 

variation in, 79 
Blood pressure and velocity, physical 

laws of, 94 
Blood pressure variations, experi- 
mental, 511 
Blood velocity, variations in, 92 
Body energy, 201, 204 

measurement of, 202 
Body fluids, 19 
Body temperature, 204 
Body temperature and environ- 
ment, 207 

normal, 209 
Bony lesions, 464 

Bony lesions and blood formation, 453 
Brain, blood supply to, 70 

efferent fibers in, 332 

physiology of, 320-333 

a complex reflex center, 220 

Carbon dioxide changes in respira- 
tion, 122-127 
Carbohydrate metabolism, 195 
Carbohydrate metabolism and bony 

lesions, 517 
Carbohydrates, functions of, 197 
Cardio accelerators, 60 

center of, 61 

reflex and tonic activity of, 62 
Cardiac cycle, 49 
Cardiac impulse, 89 
Cardio-inhibition, cause of, 58 
Cardio-inhibitors, reflex action of, 58 
Cardio-inhibitory center, 57 
Centers, spinal, Burns' researches 

on, 471-492 
Cerebellum, functions of, 333 
Cerebrospinal fluid, 42 
Cerebrum, Broca's area in, 327 

extirpation of, 323, 324 

motor areas of, 330, 331 

sensory areas of, 325 

Wernecke's area in, 327 
Chemical changes in active muscle, 

250 . 

Chemistry of respiratory changes, 

122-124 
Cheyne-Stokes respiration, 128 
Choroid coat of eye, 363 
Chromophile bodies, 220 
Ciliary body, 364 
Ciliated epithelium, 229 
Circulation, discovery of, 37 

effects of respiratory movements 
on, 119 

organs of, 44 

physical factors involved in, 91 

purpose of, 19 

time of, 78 



Coagulation of blood, 32 

causes of, 33 

methods of increasing, 35 

methods of preventing, 35 
Cochlea, 355 
Cocoa and chocolate, 199 
Coffee and tea, 199 
Colon, movements of, 171 

nerve supply of, 172 
Color index, 458 
Columns of the cord, 310-314 
Complement, 26 
Conclusion, McConnell's, 400 
Conclusion to Series No. 2, 513 
Condiments, flavors, etc., 200 
Conduction paths of cord, 310-314 
Consciousness, physiology of, 493-502 
Constituents of urine, 184 
Contractile tissue, 229 
Contraction wave, 241 

voluntary contractions, nature 
of, 242 
Control work, 399 
Corpuscles, 21 

variation in number of, 21 • 
Cranial nerves, 315-319 

abducent, 316 

accessory, 318 

auditory, 317 

facial, 317 

glossopharyngeal, 317 

hypoglossal, 318 

oculo-motor, 315 

olfactory, 315 

optic, 315 

pneumogastric, 318 

trigeminal, 316 

trochlear, 316 

Defibrinated blood, 32 
Deglutition, 142, 143 
Diaphragm, movements of, 103 

innervation of, 103 
Dicrotic wave, causes of, 87 
Digestion in stomach, 150 
Drugs, effects of on stomach secre- 
tion, 150 

effects of on heart, 59 
Ductless glands, physiology of, 217 

Ear, physiology of, 353 

external, 353 

middle, 353 
Efferent fibers of brain, 332 
Enzymes, 139 

classification of, 141 

general properties of , 139 

kinds of, 141 
EquiHbrium and health, 430 
Ergograph, use of, 243 
Eye, coats of, 362-364 

physics of, 366 

physiology of, 362 

refractive media of, 367 



Erythroblasts, 22 
Erythrocytes, 21, 22, 23, 458 
Excretory organs, 181 
Experimental work, McConnell, 380 

Fats, digestion in intestines, 156 

functions of, 198 

metabolism of, 198 

source of, 198 
Fibrin, 32 
Fibrinogen, 32-33 
Foods, 137 

composition of, 137 
Fundamentals of the lesion, 438 

Gastric secretion and digestion, 148 

methods of study of, 148 
General principles, 412 
Glycosuria, see Series No. 4, 517 

Hearing, theory of, 355 
Heat production in body 204 

regulation of loss of, 205 

regulating mechanism, nerve 
supply of, 206 
Heart, 45 

beat, causes of, 50 

blood pressure in, 48 

muscle, tone of, 54 

nerve supply to, 55 

sounds , 87, 88 

valves, 46 
Hemoglobin, 457 
Hemoglobin, 22, 23 

compounds, 24 

crystals, 25 

determination of, 24 
Hematopoietic organs, 22 
Hemolysis, 25 
Hemolysins, 26 
Hemolytic agents, 25 
Hormones of stomach, 149 
Hunger, sensation of, 352 
Hyperthyroidism, 225 

Idiomuscular contractions, 241 
Impure air, effects of breathing, 125 
Induction coil, 89 
Inorganic salts, 199 
Internal secretions, 213-225 

methods of study of, 215 
Intestines, absorption in, 164-167 
Intestines, movements in, 170 
Intrapulmonic and intrathoracic pres- 
sure, 115 
Intravascular clotting, 35 
Iris, 364 

nerve control of, 364 

Kidneys, excretions of, 184 
formation of urine in, 181 
internal secretions of, 225 
nerve supply to, 181 

Knee jerk, 308 



Lactic acid in stomach, 151 
Lesion, osteopathic, 373 

dissection of, 382 

microscopic findings in, 384 
Leucocytes, 459 

Amphophiles, 460 

Basophiles, 460 

Eosinophils, 460 

Lymphocytes, 459 

Neutrophils, 459 
Leucocytes, 27 

classification of, 27 

functions of, 29 

normal number of, 27 

phagocytic action of, 29 

variation in, 27 
Liver and pancreas, relations of, 520 
Liver, bile formation in, 158 

functions of, 160 
Lipase, gastric, 151. 
Lungs, nerve supply to, 104 
Lymph flow, 41 

functions of, 41 - 

osteopathic considerations con- 
cerning, 43 
Lymph, 20, 39 

general properties of, 39 

origin and formation of, 39 - 
Lymph vessels, 40 
Lymphagogues, 40 
Lymphocytes, 27 

Mast cells, 29 

Mastication, 142 

Metabolism, 193-200 

of carbohydrates, 195 

of fats, 198 

of proteins, 193 

Microscopic examination of the osteo- 
pathic lesion, 384 

Micturition, 184 

Movements of stomach and intes- 
tines, 168 

Muscle, artificial stimulation, 234 
blood and nerve supply to, 231 
chemical properties of, 248 
conditions affecting, 237 
contraction of, 236 
effects of curare on, 233 
elacticity and extensibility of, 232 
energy and work, 249-250 
fatigue of, 253 
general properties, 232 
heart, 231 
irritability, 233 
latent period of, 237 
physiology of, 230-255 
smooth, 231 striated, 230 
time, 236 

tissue, normal functions of, 243 
tone, relation to spinal cord, 307 

Muscle contraction, tetanic and com- 
pound, 239 



Muscle contracture, 238 

causes of, 238 
Muscle tonus, 245 

physiological significance of, 246 
Muscles of respiration, 105, 106 
Muscular contraction, causes of, 255 
Muscular rigor, 249 
Muscular work, 251 

efficiency, 252 
Muscarin, action of on heart, 59 

Neuron doctrine, 272 

Neurones, classification of, 277-280 

cortico-spinal, 334 

spino-muscular, 336 

upper motor, 334 
Nerve cell, relation of to its processes, 

274 
Nerve conduction, 261 

conductivity, variation in, 262 

impulse, 261 
Nerve control of the iris, 364 
Nerve degeneration, 275 

regeneration, 276 
Nerve energy, source of, 280, 305 
Nerve fibers, afferent and efferent, 
' 265-266 

classification of, 267 

direction of conduction in, 265 

functional differences in, 265 
Nerve force, measurement of, 349 
Nerves, somatic afferent, 416 

somatic motor, 417 

visceral afferent, 416 

visceral efferent, 417 
Nerve supply to the alimentary 
canal, 173 

to colon, 172 

to blood vessels, 64 

to bone marrow, 453 

to diaphragm, 514-516 

to kidneys, 181 

to the heart, 55 

to lungs, 104 

to muscles of respiration, 107 

to the pancreas, 154 

to salivary glands, 145 

to the stomach, 149 

to taste buds, 360 
Nerve reflexes, 283 
Nerve tissue, changes resulting from 
lesion in, 426 

fiber, structure and function 
of, 259 

medullated and non-medulla- 
ted, 260 
Neuro-muscular mechanism, 242 
Nerve trophism, 302 
Nervous system, symphathetic, 

effects of lesion on, 419 
Normalization of animals for experi- 
mental work, 528 
Nutrition and spinal lesions, 549-556 



Olfactory sensations, 358 

conduction of, 358 

properties of, 358 
Opsonins, 29 

Whiting's researches on, 503-505 
Osteopathic centers, 436 
Osteopathic considerations of physi- 
ology of the liver, 162 

of kidneys, 186 

Osteopathic lesions, 464 

effects of on carbohydrate meta- 

abolism, 517 
effects of experimental, 509 
effects on functions of the colon, 

172 
effects of on gastric digestion, 153 
effects of on monkeys, 549 
effects of on nutrition, see series 

No. 12 
effects of on viscera, 396 
experimental evidence of, 509 
fundamentals of, 438 
immediate effects of, 541 
McConnelTs researches, 373-444 
nerve changes resulting from, 426 
pathologic changes from, 431 
practical considerations of, 433 
production of in animals, 529 
urinary changes from. See Series 

Nos. 4 and 12 

Osteopathic stimulation and inhibi- 
tion, 536 

Osteopathic stimulation, See Series 
Nos. 16 and 17. 

Osteopathic theory, 406 

Osteopathic therapy, experimental 
evidence, 549 

Ovaries, 221, 222 

Oxygen, changes in respiration, 122- 
124 

Oxyhemoglobin, 25 

Pain, sense of, 346 

Pancreas and liver, relations of, 520 

Pancreas, internal secretions of, 217 

experimental work on, 518 

methods of study of, 154 

secretory nerves of, 154 
Pancreatic juice, properties of, 157 
Paralysis, from lesions of gray and 
white matter, 338 

due to trauma of cord, 339 
Parathyroid glands, 225 
Pericardium, 48 
Phagocytes, 29 
Phrenic nerve, 514-516 
Physics of the eye, 366 
Physical factors involved in circula- 
tion, 91 
P. M. I., the, 89 
Pineal body, 223 



Pituitary body, 222 

Plasma, 21, 25 

Plethysmograph, 65 

Pleura, 100 

Post-mortem examination after lesion, 

530 
Polymorphonuclear leucocytes, 28 
Practical application of principles, 442 
Practical considerations of the lesion, 

433 
Protein digestion in intestines, 156 
Proteins, digestion of, 150 
Proteins of the blood, 31 
Protein metabolism, 193 
Protein sparers, 194 
Properties of urine, 184 
Prothrombin, 33 
Pupil, causes of constriction of, 365 

dilation of, 366 
Pulse, 85-87 

Reflex action of cardio-inhibitory 

center, 58 
Reflex action, effects of drugs on, 301 

effects of osteopathic lesions 
on, 301 

relation of cord to, 300 
Refraction, abnormal, causes of, 368 

normal and abnormal, 368 
Reflexes, inhibition of, 298 

kinds of, 287-294 

osteopathic significance of, 297 

symphatetic, experimental work 
on, 534 
Reflex action, animals, 295 

Burns' researches on, 462-470 

paths, 295 

specificity of, 286 
Reflex arc, 285 
Reflex mechanism, 283 
Rennin, action of, 151 
Respiration, 99 

active and passive, 101 

chemical changes in, 121 

cutaneous, 189 

diaphragmatic, 112 

external and internal, 99 

movements and rate of, 101 

movements of, 111 

muscles of, 105, 106 
Respiratory organs, 99 
Respiratory center, action of, 107 

secondary, 108 

regulation of, 109 
Respiratory changes, physics of, 121 
Respiratory movements, causes of, 
102 

abnormal, 128 

effects of exercise on, 129 

measurement of, 112 
Respiratory quotient, 132 
Retina, functions of, 363 



Saccule, 357 

Saliva, general properties of, 146 

functions of, 147 

variation in secretion of, 146 
Salivary glands, 144 

nerve supply of, 145 
Saliva and salivary digestion, 144 
Sclerotic coat of eye, 362 
Sebum, secretion of, 189 
Secretion theory of kidneys, 183 
Secretagogues of stomach, 149 
Secretion and digestion in the intes- 
tines, 154 

Secretion in intestines, 157 

Semicircular canals, 356 

Sensation of hunger, 352 

Sensations, cutaneous, 350 
internal and external, 346 
special classification of, 345 

Sensibilities, deep, 351 

Sensory disturbances from cord 

lesions, 340 . 
Sense of taste, 359 

of smell, 358 

of thirst, 351 

Series No. 2, 510 
Series No. 3, 514 
Series No. 4, 517 
Series No. 5, 534 
Series No. 7, 536 
Series No. 9, 539 
Series No. 12, 549 
Series No. 15, 558 
Series No. 16, 560 
Serum-globulin, 32 

albumin, 32 
Skin, functions of, 187 
Smell, sense of, 358 

end organs of, 358 

mechanism of, 358 

sensativeness of, 359 
Sphincter valves, 175 

regulation of, 175 
Specific nerve energies, theory of, 347 
Specific nerve energies, mechanism 

of, 269 
Sphygmograph, 86 
Sphygmogram, 86 
Spinal areas, 512 
Spinal centers, Burns' researches on, 

471-492 
Spinal cord, effects of complete div- 
ision of, 340 
Spinal cord centers, 308 

effects of extirpation of, 307 
Spinal cord pathways, 514 
Spinal shock, 339, 543-546 
Spinal stimulation, effects of, 465 
Spinal treatment, effects of intes- 
tines, 179 
Spinal strain, 546 
Spirometer, 113 



Spleen, physiology of, 180 
Starch, digestion of, 150 
Stimulants, 199 

Stimulation and inhibition, osteo- 
pathic, 536 
Stimulation, visceral effects of, 466 

spinal, effects of, 465 
Stomach, absorption in, 151 

osteopathic considerations, 177 

movements of, 168 

methods of study of, 169 

secretory nerves to, 149 
Stroma, 21 
Sweat, constituents of, 188 

osteopathic considerations, 189 
Sweat glands, 187 

constituents of, 188 
Sympathetic nerves. (See autonomics ) 
Synapse, nature of, 272-274 

Taste sensations, fundamental, 360 

properties of, 360 
Taste, sense of, 359 
Testes, 221 
Tetanus, muscular, 239 

pathological, 240 
Thirst, sense of, 351 
Thoracic cavity, 101 
Thrombin, 33 
Thrombokinase, 33 
Thymus gland, 220 
Thyroid glands, 224 
Transitional leucocytes, 28 
Tracts of the cord, 310-314 
Treatment, specific, 436 

Utricle, 357 

Vagus nerve, 55 

inhibitory action of, 56 
Vascular changes resulting from les- 
ion, 423 
Vaso-constrictors to head and neck, 
72 

to abdominal viscera, 73 

to genital organs, 75 

to upper limbs, 72 
Vaso-constrictors, 68 

structures supplied by, 70 
Vaso-dilators, 75 

to cranial, 76 

nature of action of, 77 

spinal autonomics, 76 
Vasomotor centers, 66 

reflexes, 67 
Vasomotor supply to pelvic viscera, 

74 
Vasomotor fibers, 64 

kinds of, 64 
Velocity of blood flow, 78 
Viscus, effects of osteopathic lesions 

on a, 396 
Volume index, 458 



AUG I 1913 



HI 



Studies in the Osteopathic Sciences 



BY 



LOUISA BURNS, M. S., D. O., D. Sc. O,. 

Professor of Physiology, The Pacific College of Osteopathy. 



Volume I — Basic Principles. 

A discussion of those facts of biology and physi- 
ology upon which osteopathic practice is based; the ex- 
perimental demonstration of the effects of bony lesions, 
illustrations, glossary, bibliography. 

Volume II — The Nerve Centers. 

A description of the nerve centers and their con- 
stituent neurons; discussions of the manner in which the 
activities of the nerve centers may be disturbed, with 
especial reference to the osteopathic principles, accounts 
of original work; freely illustrated; tables of the nerve 
centers and tracts, glossary, bibliography. 

Volume III — The Physiology of Consciousness. 

A description of the cerebral cortex and its relations; 
a discussion of consciousness and its varying states in 
terms of the physiological activities of the cortical neurons; 
comparison of the theories of psychology; illustrations, 
glossary, bibliography. 

Volume IV — The Blood. 

A description of the blood, its development, physi- 
ology, morphology, and pathology; osteopathic methods 
applied to blood variations; colored plates; glossary, 
bibliography. 

Price $4.00 per volume, postpaid. 



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Address DR. M . L. BURNS 

The Pacific College of Osteopathy LOS ANGELES, CAL. 



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